Battery technology upgrade: hard carbon anode for sodium ion battery
Graphite mainly has a hexagonal structure with ABAB stacking and a rhombic structure with ABCABC stacking. The two phases of graphite can be interconverted, and processes such as mechanical treatment can lead to an increase in the proportion of phase composition in graphite, and annealing treatment at high temperatures will generate a thermodynamically more stable phase.
Table of Contents
What is amorphous carbon
The difference between graphite system and amorphous carbon
Amorphous carbon mainly includes hard carbon anode material and soft carbon, which usually consists of randomly distributed graphitized microstructures, twisted graphene nanosheets and pores between the above referred microstructures, and lacks an ordered stacking structure.
Graphite has become the most common lithium ion battery anode material for commercial lithium-ion batteries due to its long-range ordered stacking structure with good electrical conductivity, high specific capacity, and good cycling performance, and its raw material sources are mainly asphalt, petroleum coke, and natural graphite, with layer spacing around 0.335 to 0.34 nm.
Hard carbon anode material is non-graphitized carbon, which is difficult to graphitize even when heated to 2800°C. Its structure is highly disordered and redoxed. Its structure is highly disordered and has a low redox potential, which is considered as a more ideal anode material for sodium ion battery.
Selection of carbon
Although graphite has a good lithium storage capacity and plays an important role in the field of lithium ion batteries, it cannot be a suitable anode material for sodium ion batteries because of the large radius of sodium ions, which hinders the embedding and disembedding of sodium ions during charging and discharging, and people have tried various methods to improve the sodium storage performance of graphite, but the results are not satisfactory so far.
The first method is to expand the spacing of graphite layers to improve its sodium storage performance. It was found that the specific capacity of expanded graphite with a layer spacing of 0.43 nm was 184 mAh/g after 2000 cycles at 5C multiplicity, and the capacity retention rate was 73.92%, but the ordered structure in expanded graphite was destroyed from X-ray diffraction spectrum, which is essentially the amorphization of expanded graphite. It allows more Na+ to be reversibly de-embedded in the graphite, but this reduced oxide graphite still suffers from low ICE, while the storage mechanism of Na+ in the reduced oxide graphite is still unclear.
Amorphous carbon is also used in practice due to its larger layer spacing and disordered microcrystalline structure, which is more favorable for sodium ion embedding and detachment. In the case of soft carbon, it has a similar structure to graphite but is less ordered, which is more conducive to sodium intercalation than graphite and can increase the specific capacity at low current density. The lower specific surface area and surface defects of soft carbon can reduce the consumption of ester electrolyte and help to improve ICE.
From the commercialization point of view, the soft carbon precursors are made of anthracite coal, which is cheaper, with lower price, high carbonization yield, good safety and certain electrochemical performance, and has good commercialization potential. From the application scenario, the unmodified capacity is 200-220mAh/g, and the charge/discharge area is mainly slope, which is suitable for high power scenario. As far as hard carbon anode material is concerned, it has a more complex structure at the molecular level compared to the long-range ordered layered structure of graphite.
The unique structure of hard carbon anode material allows for various types of reversible sodium storage sites, including: sodium storage by embedding reactions, sodium storage by forming atomic clusters within closed pores, sodium storage by capacitive adsorption on the surface in contact with the electrolyte, and sodium storage by pseudocapacitance on the internal surface at defect-related sites.
Material charging and discharging area has slope section and platform section, and the general specific capacity can reach 300-350mAh/g, and after optimized modification, it can reach 400mAh/g, which will exceed the theoretical specific capacity of lithium graphite (372mAh/g).
In summary, graphite is an important anode material for Li-ion batteries, but its application in sodium ion batteries is greatly limited by the small layer spacing and the inability to form thermally stable intercalation compounds with graphite, although the problem can be improved by expanding the layer spacing with expanded graphite and adjusting the electrolyte, but there are still problems such as low ICE and poor electrolyte stability.
On the contrary, the low order of soft carbon is more conducive to sodium storage and has cheaper precursor cost. The complex molecular level structure of hard carbon anode material creates many types of sodium storage active sites, and after optimized modification, it can exceed the theoretical specific capacity of lithium graphite, which has strong commercialization potential. Therefore, it is relatively more appropriate to choose amorphous carbon, especially hard carbon anode material, for sodium ion carbon anode material.
Potential competitors of hard carbon anode material
● Silicon-based anode materials
The advantages of silicon-based anode materials include relatively high theoretical capacity; natural abundance (silicon is an abundant element on earth); and suitable electrochemical potential – less likely to form “lithium dendrites” than hard carbon anode materials. “. Of course, the disadvantages are equally obvious: the inevitable volume changes in silicon materials can lead to structural rupture or pulverization of the silicon-based electrodes, which in turn leads to uncontrolled growth of SEI films; and their inherent poor conductivity.
● Lithium titanate anode material
Lithium titanate anode material is also a possible future battery cathode material, its advantages include: simple preparation method, high charging and discharging platform, stable cycle, high Coulomb efficiency; “zero strain” material, the volume of the crystal in the reaction cycle to maintain a stable range (effectively solve the phenomenon of electrode material shedding due to volume changes); stable working voltage Lithium ions will not precipitate lithium dendrites on the electrode; stable electrode voltage platform.
The disadvantages also exist: low conductivity and lithium ion diffusion coefficient, severe polarization of the electrode under high current density makes the electrode capacity decrease sharply, the formation of SEI film makes the electrode and electrolyte contact for a long time to produce adverse reactions. Here are top 5 lithium titanate battery manufacturers, if you are interested, please click to view.
● Tin-based anode materials
Tin-based anode materials are now attracting a lot of attention from scholars and entrepreneurs. Its advantages are: abundant resources; high theoretical capacity; higher embedded lithium potential than lithium precipitation potential, avoiding lithium deposition at high multipliers; and high stacking density. The disadvantage is that the volume expansion of Sn during cycling reaches 259% (Li-ion batteries) and 423% (sodium-ion batteries) respectively, which seriously affects the cycling performance.
What determines the properties of amorphous carbon
Hard carbon anode material vs. soft carbon
Amorphous carbon materials can be classified into hard carbon anode material and soft carbon according to the ease of graphitization. Soft carbon is usually a carbon material that can be graphitized after high temperature treatment (above 2800°C), and the disordered structure can be easily eliminated.
Hard carbon anode material is usually a carbon material that cannot be completely graphitized even after high temperature treatment (above 2800°C), and the disordered structure is difficult to be eliminated at high temperature. At low and medium temperatures (1000-1600°C), there is no obvious boundary between soft carbon and hard carbon anode material, and they can be called amorphous carbon.
Although soft carbon has a high capacity value, its fast decay rate causes obstacles to practical applications; hard carbon anode material is easier to prepare, has a higher cycle life, and has gained some practical applications. Compared with soft carbon, hard carbon anode material has more disordered structure, higher defect concentration, higher heteroatom content and larger distance between graphite layers, and more closed pore structure.
This facilitates more storage sites and diffusion pathways for Na+ ions. However, the economics of hard carbon anode material is slightly inferior compared to that of soft carbon. Among the sodium ion batteries, hard carbon anode material is dominant in current applications with its advantages. In addition, the low cost, sustainability and simplicity of preparation provide more possibilities for commercialization of hard carbon anode material.
Precursors
Soft carbon and hard carbon anode material depend mainly on the nature of the precursor. During the carbonization process, the ability of the precursors to appear in a fused state over a wide temperature range is necessary for the final carbon (coke) to be graphitized. This fusion state allows the rearrangement of carbon layers to form long-range ordered lamellar structures where gases from thermal decomposition can easily escape, while the carbon content and density of the residue increases.
Amorphous carbon is usually produced by pyrolysis of organic precursors at temperatures of 500-1500°C. The end product after pyrolysis is hard carbon. Whether the end product of pyrolysis is hard carbon anode material or soft carbon depends mainly on the nature of the precursor.
The precursors are mainly classified into biomass-based, polymer-based, resin-based, and coal-based carbon materials. Biomass precursors are mainly plant roots and leaves. Polymer precursors are usually carbohydrate precursors including glucose, sucrose, starch, cellulose, and lignin, which are chemical products derived from biomass. Resin precursors mainly include phenolic resins, polyaniline and polyacrylonitrile.
The precursors used to produce hard carbon anode material are mainly biomass, resin and polymer precursors. The precursors used to prepare soft carbon materials mainly include petrochemical raw materials and their downstream products, such as coal, asphalt and petroleum coke, etc. However, the direct carbonized soft carbon materials show low reversible capacity in sodium ion batteries.
Amorphous carbon has excellent reversible capacity and cycling performance, and is expected to be commercialized after cost control. hard carbon anode material has high gram capacity but high cost; soft carbon material has low gram capacity but has the advantage of cost performance. The core of sodium ion battery anode material is how to reduce its cost.
The core technical route of hard carbon anode material preparation includes raw material selection and pretreatment, cross-linking and curing, carbonization and purification. Different types of precursors also have process differences in the preparation of hard carbon anode material anode material.
The temperature control, gas atmosphere and heating time of the intermediate steps affect the pore size, purity, oxygen content and specific surface area of the anode material. It also indirectly affects the first time efficiency, energy density, safety and other factors of the battery.
Organic polymer precursors are relatively simple and controllable in molecular structure, and can be designed according to the needs of the relevant molecular structure, so they are an excellent precursor for the preparation of carbon materials and have received much attention.
Not like cathode materials, the organic polymers are prepared by catalytic polymerization of organic small molecules and have the advantages of obtaining regular shaped hard carbon anode material structures and simple synthesis process, which is of high research value for the future mass production and application of hard carbon anode material materials.
Biomass-based precursors are abundant and have sustainable use and low cost characteristics. They usually contain a large amount of C, with some O, H and even some other heteroatoms such as N, S, P, etc. Biomass is a good choice for the production of renewable and sustainable precursors for low-cost and high-performance hard carbon anode materials. The conversion of biomass into hard carbon anode material is simple, such as direct carbonization, hydrothermal carbonization (HTC), physical or chemical activation, etc.
Biomasses such as banana peel, peat moss, rice husk, cotton, glucose, protein and cellulose nanocrystals have been used as anode materials for sodium ion batteries and have shown good electrochemical properties.
Asphalt, as a low-cost petrochemical by-product, is now widely used due to its low cost and high carbon content. However, asphalt base can easily form an ordered structure during high temperature cracking, so its storage capacity is very low, less than 100 mAh/g. Currently, Chinese Academy of Sciences has modified asphalt as a soft carbon precursor and resin type as a hard carbon anode material precursor by compounding them to increase the sodium storage capacity to 300 mAh/g.
Demand for hard carbon anode material
Li-ion battery hard carbon anode material demand forecast
At present, most of the Chinese companies laying out hard carbon anode material have applied it to lithium-ion batteries and have achieved rich results and practices. In the choice of anode material for lithium-ion batteries, graphite has become the main raw material.
The structural defects of graphite anode limit its cycle stability and charge/discharge efficiency as the anode material for lithium-ion batteries, while the isotropic structural characteristics of hard carbon anode material, the larger layer spacing, and the good multiplication performance of lithium ion spreading speed during charge/discharge make hard carbon anode material a better choice in the field of lithium-ion batteries.
The hard carbon anode material has isotropic structural characteristics, larger layer spacing, fast lithium ion dispersion during charging and discharging, and good multiplicative performance, so that the hard carbon anode material has a better application in the field of lithium-ion batteries.
In 2021, the shipment structure of China’s lithium battery anode products is still dominated by artificial graphite, accounting for 84%; natural graphite is the second largest segment of anode products, accounting for 14%; the rest of the anode materials are 2%. Among the other segments, hard carbon anode material and soft carbon material are the main parts. According to the data, soft carbon and hard carbon anode material accounted for 1.7% of the global shipments of lithium battery anode materials in 2015.
In recent years, the application of hard carbon anode material in lithium batteries has also made some industrial progress, so we predict that in the next few years, hard carbon anode material will be an application material for lithium battery anode, accounting for about 2%. The future shipments of lithium batteries are showing a high trend.
As the global penetration rate of new energy vehicles continues to rise, the demand for power batteries and energy storage batteries will continue to grow at a high rate, and before 2030, other battery systems are still difficult to large-scale industrial development, lithium-ion batteries will remain the mainstream technology route.
As the proportion of hard carbon anode material in lithium battery anode material is not high, the pull of lithium for hard carbon anode material material will be small. According to the calculation of hard carbon anode material 300mah/g capacity, 3.2V voltage platform, 1GWh lithium battery consumes about 1125 tons of hard carbon anode material, we expect that by 2025 there will be about 35,000 tons of hard carbon anode We expect that about 35,000 tons of hard carbon anode material will be used for the production of lithium battery anode material by 2025.
Demand forecast for hard carbon anode material for sodium batteries
Characteristics of hard carbon anode material and application scenarios in sodium ion batteries: Recently, a research team tested the electrochemical properties of hard carbon anode material material and found that a sample presented a high specific capacity of 369.8 mAh/g when it was used as the anode material for sodium ion batteries; hard carbon anode material has a low redox potential (0.1-1.0 V).
Due to the widespread use of biomass-related precursors of hard carbon anode material precursors, it is also hard carbon anode material that has become a green choice for battery anode materials. To conclude, in sodium ion battery applications, hard carbon anode material has a greater layer spacing and can form thermally stable intercalation compounds with sodium compared to graphite, and has a greater sodium storage capacity compared to soft carbon, which has a better application scenario in sodium ion battery electrodes, sodium ion capacitor electrodes, and sodium-based double ion battery electrodes, which are sodium ion battery related fields.
After comparing and analyzing the characteristics of sodium ion battery, lithium iron phosphate battery, ternary battery and lead-acid battery in terms of energy density, cycle life, average voltage, safety, multiplier performance, fast charging performance and high and low temperature performance, we believe that sodium ion battery has a good prospect in the application scenarios of electric two-wheelers, low-speed electric vehicles, energy storage and start-stop.
Assuming that the replacement ratio of sodium battery is 5%, 15% and 25% from 2023 to 2025, the corresponding installed capacity of sodium battery is 9GWh, 33.7GWh and 72.5GWh respectively. We expect that the demand for hard carbon anode material for sodium batteries in 2023-2025 will be 0.97 million tons, 36.2 million tons and 7.79 million tons.
Summing up the two parts of hard carbon anode material demand, we estimate that the total demand for hard carbon anode material in 2021 will be about 12,700,000 tons, while the total demand for hard carbon anode material in 2025 is expected to grow significantly to about 112,900,000 tons, with a compound annual growth rate of 72.8%. The compound growth rate reaches 72.8%.
Battery technology upgrade: hard carbon anode for sodium ion battery
What is amorphous carbon
The difference between graphite system and amorphous carbon
Amorphous carbon mainly includes hard carbon anode material and soft carbon, which usually consists of randomly distributed graphitized microstructures, twisted graphene nanosheets and pores between the above referred microstructures, and lacks an ordered stacking structure.
Graphite has become the most common lithium ion battery anode material for commercial lithium-ion batteries due to its long-range ordered stacking structure with good electrical conductivity, high specific capacity, and good cycling performance, and its raw material sources are mainly asphalt, petroleum coke, and natural graphite, with layer spacing around 0.335 to 0.34 nm.
Hard carbon anode material is non-graphitized carbon, which is difficult to graphitize even when heated to 2800°C. Its structure is highly disordered and redoxed. Its structure is highly disordered and has a low redox potential, which is considered as a more ideal anode material for sodium ion battery.
Selection of carbon
Although graphite has a good lithium storage capacity and plays an important role in the field of lithium ion batteries, it cannot be a suitable anode material for sodium ion batteries because of the large radius of sodium ions, which hinders the embedding and disembedding of sodium ions during charging and discharging, and people have tried various methods to improve the sodium storage performance of graphite, but the results are not satisfactory so far.
The first method is to expand the spacing of graphite layers to improve its sodium storage performance. It was found that the specific capacity of expanded graphite with a layer spacing of 0.43 nm was 184 mAh/g after 2000 cycles at 5C multiplicity, and the capacity retention rate was 73.92%, but the ordered structure in expanded graphite was destroyed from X-ray diffraction spectrum, which is essentially the amorphization of expanded graphite. It allows more Na+ to be reversibly de-embedded in the graphite, but this reduced oxide graphite still suffers from low ICE, while the storage mechanism of Na+ in the reduced oxide graphite is still unclear.
Amorphous carbon is also used in practice due to its larger layer spacing and disordered microcrystalline structure, which is more favorable for sodium ion embedding and detachment. In the case of soft carbon, it has a similar structure to graphite but is less ordered, which is more conducive to sodium intercalation than graphite and can increase the specific capacity at low current density. The lower specific surface area and surface defects of soft carbon can reduce the consumption of ester electrolyte and help to improve ICE.
From the commercialization point of view, the soft carbon precursors are made of anthracite coal, which is cheaper, with lower price, high carbonization yield, good safety and certain electrochemical performance, and has good commercialization potential. From the application scenario, the unmodified capacity is 200-220mAh/g, and the charge/discharge area is mainly slope, which is suitable for high power scenario. As far as hard carbon anode material is concerned, it has a more complex structure at the molecular level compared to the long-range ordered layered structure of graphite.
The unique structure of hard carbon anode material allows for various types of reversible sodium storage sites, including: sodium storage by embedding reactions, sodium storage by forming atomic clusters within closed pores, sodium storage by capacitive adsorption on the surface in contact with the electrolyte, and sodium storage by pseudocapacitance on the internal surface at defect-related sites.
Material charging and discharging area has slope section and platform section, and the general specific capacity can reach 300-350mAh/g, and after optimized modification, it can reach 400mAh/g, which will exceed the theoretical specific capacity of lithium graphite (372mAh/g).
In summary, graphite is an important anode material for Li-ion batteries, but its application in sodium ion batteries is greatly limited by the small layer spacing and the inability to form thermally stable intercalation compounds with graphite, although the problem can be improved by expanding the layer spacing with expanded graphite and adjusting the electrolyte, but there are still problems such as low ICE and poor electrolyte stability.
On the contrary, the low order of soft carbon is more conducive to sodium storage and has cheaper precursor cost. The complex molecular level structure of hard carbon anode material creates many types of sodium storage active sites, and after optimized modification, it can exceed the theoretical specific capacity of lithium graphite, which has strong commercialization potential. Therefore, it is relatively more appropriate to choose amorphous carbon, especially hard carbon anode material, for sodium ion carbon anode material.
Potential competitors of hard carbon anode material
● Silicon-based anode materials
The advantages of silicon-based anode materials include relatively high theoretical capacity; natural abundance (silicon is an abundant element on earth); and suitable electrochemical potential – less likely to form “lithium dendrites” than hard carbon anode materials. “. Of course, the disadvantages are equally obvious: the inevitable volume changes in silicon materials can lead to structural rupture or pulverization of the silicon-based electrodes, which in turn leads to uncontrolled growth of SEI films; and their inherent poor conductivity.
● Lithium titanate anode material
Lithium titanate anode material is also a possible future battery cathode material, its advantages include: simple preparation method, high charging and discharging platform, stable cycle, high Coulomb efficiency; “zero strain” material, the volume of the crystal in the reaction cycle to maintain a stable range (effectively solve the phenomenon of electrode material shedding due to volume changes); stable working voltage Lithium ions will not precipitate lithium dendrites on the electrode; stable electrode voltage platform.
The disadvantages also exist: low conductivity and lithium ion diffusion coefficient, severe polarization of the electrode under high current density makes the electrode capacity decrease sharply, the formation of SEI film makes the electrode and electrolyte contact for a long time to produce adverse reactions. Here are top 5 lithium titanate battery manufacturers, if you are interested, please click to view.
● Tin-based anode materials
Tin-based anode materials are now attracting a lot of attention from scholars and entrepreneurs. Its advantages are: abundant resources; high theoretical capacity; higher embedded lithium potential than lithium precipitation potential, avoiding lithium deposition at high multipliers; and high stacking density. The disadvantage is that the volume expansion of Sn during cycling reaches 259% (Li-ion batteries) and 423% (sodium-ion batteries) respectively, which seriously affects the cycling performance.
What determines the properties of amorphous carbon
Hard carbon anode material vs. soft carbon
Amorphous carbon materials can be classified into hard carbon anode material and soft carbon according to the ease of graphitization. Soft carbon is usually a carbon material that can be graphitized after high temperature treatment (above 2800°C), and the disordered structure can be easily eliminated.
Hard carbon anode material is usually a carbon material that cannot be completely graphitized even after high temperature treatment (above 2800°C), and the disordered structure is difficult to be eliminated at high temperature. At low and medium temperatures (1000-1600°C), there is no obvious boundary between soft carbon and hard carbon anode material, and they can be called amorphous carbon.
Although soft carbon has a high capacity value, its fast decay rate causes obstacles to practical applications; hard carbon anode material is easier to prepare, has a higher cycle life, and has gained some practical applications. Compared with soft carbon, hard carbon anode material has more disordered structure, higher defect concentration, higher heteroatom content and larger distance between graphite layers, and more closed pore structure.
This facilitates more storage sites and diffusion pathways for Na+ ions. However, the economics of hard carbon anode material is slightly inferior compared to that of soft carbon. Among the sodium ion batteries, hard carbon anode material is dominant in current applications with its advantages. In addition, the low cost, sustainability and simplicity of preparation provide more possibilities for commercialization of hard carbon anode material.
Precursors
Soft carbon and hard carbon anode material depend mainly on the nature of the precursor. During the carbonization process, the ability of the precursors to appear in a fused state over a wide temperature range is necessary for the final carbon (coke) to be graphitized. This fusion state allows the rearrangement of carbon layers to form long-range ordered lamellar structures where gases from thermal decomposition can easily escape, while the carbon content and density of the residue increases.
Amorphous carbon is usually produced by pyrolysis of organic precursors at temperatures of 500-1500°C. The end product after pyrolysis is hard carbon. Whether the end product of pyrolysis is hard carbon anode material or soft carbon depends mainly on the nature of the precursor.
The precursors are mainly classified into biomass-based, polymer-based, resin-based, and coal-based carbon materials. Biomass precursors are mainly plant roots and leaves. Polymer precursors are usually carbohydrate precursors including glucose, sucrose, starch, cellulose, and lignin, which are chemical products derived from biomass. Resin precursors mainly include phenolic resins, polyaniline and polyacrylonitrile.
The precursors used to produce hard carbon anode material are mainly biomass, resin and polymer precursors. The precursors used to prepare soft carbon materials mainly include petrochemical raw materials and their downstream products, such as coal, asphalt and petroleum coke, etc. However, the direct carbonized soft carbon materials show low reversible capacity in sodium ion batteries.
Amorphous carbon has excellent reversible capacity and cycling performance, and is expected to be commercialized after cost control. hard carbon anode material has high gram capacity but high cost; soft carbon material has low gram capacity but has the advantage of cost performance. The core of sodium ion battery anode material is how to reduce its cost.
The core technical route of hard carbon anode material preparation includes raw material selection and pretreatment, cross-linking and curing, carbonization and purification. Different types of precursors also have process differences in the preparation of hard carbon anode material anode material.
The temperature control, gas atmosphere and heating time of the intermediate steps affect the pore size, purity, oxygen content and specific surface area of the anode material. It also indirectly affects the first time efficiency, energy density, safety and other factors of the battery.
Organic polymer precursors are relatively simple and controllable in molecular structure, and can be designed according to the needs of the relevant molecular structure, so they are an excellent precursor for the preparation of carbon materials and have received much attention.
Not like cathode materials, the organic polymers are prepared by catalytic polymerization of organic small molecules and have the advantages of obtaining regular shaped hard carbon anode material structures and simple synthesis process, which is of high research value for the future mass production and application of hard carbon anode material materials.
Biomass-based precursors are abundant and have sustainable use and low cost characteristics. They usually contain a large amount of C, with some O, H and even some other heteroatoms such as N, S, P, etc. Biomass is a good choice for the production of renewable and sustainable precursors for low-cost and high-performance hard carbon anode materials. The conversion of biomass into hard carbon anode material is simple, such as direct carbonization, hydrothermal carbonization (HTC), physical or chemical activation, etc.
Biomasses such as banana peel, peat moss, rice husk, cotton, glucose, protein and cellulose nanocrystals have been used as anode materials for sodium ion batteries and have shown good electrochemical properties.
Asphalt, as a low-cost petrochemical by-product, is now widely used due to its low cost and high carbon content. However, asphalt base can easily form an ordered structure during high temperature cracking, so its storage capacity is very low, less than 100 mAh/g. Currently, Chinese Academy of Sciences has modified asphalt as a soft carbon precursor and resin type as a hard carbon anode material precursor by compounding them to increase the sodium storage capacity to 300 mAh/g.
Demand for hard carbon anode material
Li-ion battery hard carbon anode material demand forecast
At present, most of the Chinese companies laying out hard carbon anode material have applied it to lithium-ion batteries and have achieved rich results and practices. In the choice of anode material for lithium-ion batteries, graphite has become the main raw material.
The structural defects of graphite anode limit its cycle stability and charge/discharge efficiency as the anode material for lithium-ion batteries, while the isotropic structural characteristics of hard carbon anode material, the larger layer spacing, and the good multiplication performance of lithium ion spreading speed during charge/discharge make hard carbon anode material a better choice in the field of lithium-ion batteries.
The hard carbon anode material has isotropic structural characteristics, larger layer spacing, fast lithium ion dispersion during charging and discharging, and good multiplicative performance, so that the hard carbon anode material has a better application in the field of lithium-ion batteries.
In 2021, the shipment structure of China’s lithium battery anode products is still dominated by artificial graphite, accounting for 84%; natural graphite is the second largest segment of anode products, accounting for 14%; the rest of the anode materials are 2%. Among the other segments, hard carbon anode material and soft carbon material are the main parts. According to the data, soft carbon and hard carbon anode material accounted for 1.7% of the global shipments of lithium battery anode materials in 2015.
In recent years, the application of hard carbon anode material in lithium batteries has also made some industrial progress, so we predict that in the next few years, hard carbon anode material will be an application material for lithium battery anode, accounting for about 2%. The future shipments of lithium batteries are showing a high trend.
As the global penetration rate of new energy vehicles continues to rise, the demand for power batteries and energy storage batteries will continue to grow at a high rate, and before 2030, other battery systems are still difficult to large-scale industrial development, lithium-ion batteries will remain the mainstream technology route.
As the proportion of hard carbon anode material in lithium battery anode material is not high, the pull of lithium for hard carbon anode material material will be small. According to the calculation of hard carbon anode material 300mah/g capacity, 3.2V voltage platform, 1GWh lithium battery consumes about 1125 tons of hard carbon anode material, we expect that by 2025 there will be about 35,000 tons of hard carbon anode We expect that about 35,000 tons of hard carbon anode material will be used for the production of lithium battery anode material by 2025.
Demand forecast for hard carbon anode material for sodium batteries
Characteristics of hard carbon anode material and application scenarios in sodium ion batteries: Recently, a research team tested the electrochemical properties of hard carbon anode material material and found that a sample presented a high specific capacity of 369.8 mAh/g when it was used as the anode material for sodium ion batteries; hard carbon anode material has a low redox potential (0.1-1.0 V).
Due to the widespread use of biomass-related precursors of hard carbon anode material precursors, it is also hard carbon anode material that has become a green choice for battery anode materials. To conclude, in sodium ion battery applications, hard carbon anode material has a greater layer spacing and can form thermally stable intercalation compounds with sodium compared to graphite, and has a greater sodium storage capacity compared to soft carbon, which has a better application scenario in sodium ion battery electrodes, sodium ion capacitor electrodes, and sodium-based double ion battery electrodes, which are sodium ion battery related fields.
After comparing and analyzing the characteristics of sodium ion battery, lithium iron phosphate battery, ternary battery and lead-acid battery in terms of energy density, cycle life, average voltage, safety, multiplier performance, fast charging performance and high and low temperature performance, we believe that sodium ion battery has a good prospect in the application scenarios of electric two-wheelers, low-speed electric vehicles, energy storage and start-stop.
Assuming that the replacement ratio of sodium battery is 5%, 15% and 25% from 2023 to 2025, the corresponding installed capacity of sodium battery is 9GWh, 33.7GWh and 72.5GWh respectively. We expect that the demand for hard carbon anode material for sodium batteries in 2023-2025 will be 0.97 million tons, 36.2 million tons and 7.79 million tons.
Summing up the two parts of hard carbon anode material demand, we estimate that the total demand for hard carbon anode material in 2021 will be about 12,700,000 tons, while the total demand for hard carbon anode material in 2025 is expected to grow significantly to about 112,900,000 tons, with a compound annual growth rate of 72.8%. The compound growth rate reaches 72.8%.
There are more to check out the top 10 sodium ion battery companies in the world, silicon based anode.