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.
목차
What is amorphous carbon
The difference between graphite system and amorphous carbon
Amorphous carbon mainly includes 경질 탄소 음극 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 리튬 이온 배터리 음극 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 나트륨 이온 배터리.
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 음극 재료, 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
리튬 이온 배터리 경질 탄소 음극재 수요 예측
현재 경질 탄소 음극재를 배치하는 대부분의 중국 기업은 리튬 이온 배터리에 적용하여 풍부한 결과와 관행을 달성했습니다. 리튬 이온 배터리의 음극재 선택에 있어 흑연이 주요 원료가 되었습니다.
흑연 음극의 구조적 결함은 리튬 이온 배터리의 음극 소재로서 사이클 안정성과 충방전 효율을 제한하는 반면, 경질 탄소 음극 소재의 등방성 구조적 특성, 큰 층 간격, 충방전 시 리튬 이온 확산 속도의 우수한 증식 성능은 리튬 이온 배터리 분야에서 경질 탄소 음극 소재를 더 나은 선택으로 만들어줍니다.
경질 탄소 음극재는 등방성 구조 특성, 더 큰 층 간격, 충전 및 방전 중 빠른 리튬 이온 분산 및 우수한 증식 성능을 가지고 있으므로 경질 탄소 음극재는 리튬 이온 배터리 분야에서 더 나은 응용 분야를 가지고 있습니다.
2021년 중국 리튬 배터리 음극 제품의 출하 구조는 여전히 인조 흑연이 84%를 차지해 가장 큰 비중을 차지하고 있으며, 천연 흑연은 14%로 두 번째로 큰 음극 제품 부문이며, 나머지 음극 재료는 2%입니다. 다른 부문 중에서는 경질 탄소 음극재와 연질 탄소 소재가 주요 부품입니다. 데이터에 따르면 2015년 전 세계 리튬 배터리 음극재 출하량 중 소프트 카본과 하드 카본 음극재가 1.7%를 차지했습니다.
최근 몇 년 동안 리튬 배터리에 경질 탄소 음극재를 적용하는 것도 산업적으로 약간의 진전을 이루었으므로 향후 몇 년 내에 경질 탄소 음극재가 리튬 배터리 음극의 응용 재료가되어 약 2%를 차지할 것으로 예상합니다. 리튬 배터리의 향후 출하량은 높은 추세를 보이고 있습니다.
신에너지 자동차의 전 세계 보급률이 계속 증가함에 따라 전력 배터리와 에너지 저장 배터리에 대한 수요는 계속해서 빠른 속도로 증가 할 것이며 2030 년 이전에는 다른 배터리 시스템이 여전히 대규모 산업 발전이 어렵고 리튬 이온 배터리가 주류 기술 경로로 남아있을 것입니다.
리튬 배터리 음극재에서 경질 탄소 음극재가 차지하는 비율이 높지 않기 때문에 경질 탄소 음극재 재료에 대한 리튬의 당김은 적을 것입니다. 경질 탄소 음극재 300mah/g 용량, 3.2V 전압 플랫폼, 1GWh 리튬 배터리 계산에 따르면 약 1125톤의 경질 탄소 음극재가 소비되며, 2025년까지 약 35,000톤의 경질 탄소 음극재가 2025년까지 리튬 배터리 양극재 생산에 사용될 것으로 예상됩니다.
나트륨 배터리용 경질 탄소 음극재에 대한 수요 예측
경질 탄소 음극재의 특성과 나트륨 이온 배터리의 적용 시나리오: 최근 한 연구팀이 경질 탄소 음극 소재의 전기화학적 특성을 실험한 결과, 나트륨 이온 배터리의 음극 소재로 사용했을 때 369.8 mAh/g의 높은 비용량을 나타냈으며, 경질 탄소 음극 소재는 낮은 레독스 전위(0.1-1.0 V)를 가지고 있다는 사실을 밝혀냈습니다.
경질 탄소 음극재 전구체의 바이오매스 관련 전구체의 광범위한 사용으로 인해 배터리 음극재로 친환경적인 선택이 된 것도 경질 탄소 음극재입니다. 결론적으로 나트륨 이온 배터리 응용 분야에서 경질 탄소 음극재는 흑연에 비해 층 간격이 더 넓고 나트륨과 열적으로 안정적인 인터칼레이션 화합물을 형성할 수 있으며 연질 탄소와 비교하여 나트륨 저장 용량이 더 커서 나트륨 이온 배터리 전극, 나트륨 이온 축전기 전극 및 나트륨 기반 이중 이온 배터리 전극 등 나트륨 이온 배터리 관련 분야에서 더 나은 응용 시나리오를 가지고 있습니다.
에너지 밀도, 사이클 수명, 평균 전압, 안전성, 승수 성능, 고속 충전 성능 및 고온 및 저온 성능 측면에서 나트륨 이온 배터리, 리튬 철 인산염 배터리, 삼원계 배터리 및 납산 배터리의 특성을 비교 및 분석 한 결과 나트륨 이온 배터리는 전기 이륜차, 저속 전기 자동차, 에너지 저장 및 스타트-스톱의 응용 시나리오에서 좋은 전망을 가지고 있다고 믿습니다.
2023년부터 2025년까지 나트륨 배터리의 교체 비율이 5%, 15%, 25%라고 가정하면, 이에 해당하는 나트륨 배터리 설치 용량은 각각 9GWh, 33.7GWh, 72.5GWh입니다. 2023~2025년 나트륨 배터리용 경질 탄소 음극재 수요는 0.97만 톤, 3620만 톤, 779만 톤이 될 것으로 예상합니다.
경질 탄소 음극재 수요의 두 부분을 합산하면 2021년 경질 탄소 음극재 총 수요는 약 12,700,000톤, 2025년 경질 탄소 음극재 총 수요는 약 112,900,000톤으로 크게 성장하여 연평균 성장률이 72.8%에 달할 것으로 예상됩니다. 복합 성장률은 72.8%에 달합니다.
배터리 기술 업그레이드: 나트륨 이온 배터리용 경질 탄소 음극
What is amorphous carbon
The difference between graphite system and amorphous carbon
Amorphous carbon mainly includes 경질 탄소 음극 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 리튬 이온 배터리 음극 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 나트륨 이온 배터리.
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 음극 재료, 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
리튬 이온 배터리 경질 탄소 음극재 수요 예측
현재 경질 탄소 음극재를 배치하는 대부분의 중국 기업은 리튬 이온 배터리에 적용하여 풍부한 결과와 관행을 달성했습니다. 리튬 이온 배터리의 음극재 선택에 있어 흑연이 주요 원료가 되었습니다.
흑연 음극의 구조적 결함은 리튬 이온 배터리의 음극 소재로서 사이클 안정성과 충방전 효율을 제한하는 반면, 경질 탄소 음극 소재의 등방성 구조적 특성, 큰 층 간격, 충방전 시 리튬 이온 확산 속도의 우수한 증식 성능은 리튬 이온 배터리 분야에서 경질 탄소 음극 소재를 더 나은 선택으로 만들어줍니다.
경질 탄소 음극재는 등방성 구조 특성, 더 큰 층 간격, 충전 및 방전 중 빠른 리튬 이온 분산 및 우수한 증식 성능을 가지고 있으므로 경질 탄소 음극재는 리튬 이온 배터리 분야에서 더 나은 응용 분야를 가지고 있습니다.
2021년 중국 리튬 배터리 음극 제품의 출하 구조는 여전히 인조 흑연이 84%를 차지해 가장 큰 비중을 차지하고 있으며, 천연 흑연은 14%로 두 번째로 큰 음극 제품 부문이며, 나머지 음극 재료는 2%입니다. 다른 부문 중에서는 경질 탄소 음극재와 연질 탄소 소재가 주요 부품입니다. 데이터에 따르면 2015년 전 세계 리튬 배터리 음극재 출하량 중 소프트 카본과 하드 카본 음극재가 1.7%를 차지했습니다.
최근 몇 년 동안 리튬 배터리에 경질 탄소 음극재를 적용하는 것도 산업적으로 약간의 진전을 이루었으므로 향후 몇 년 내에 경질 탄소 음극재가 리튬 배터리 음극의 응용 재료가되어 약 2%를 차지할 것으로 예상합니다. 리튬 배터리의 향후 출하량은 높은 추세를 보이고 있습니다.
신에너지 자동차의 전 세계 보급률이 계속 증가함에 따라 전력 배터리와 에너지 저장 배터리에 대한 수요는 계속해서 빠른 속도로 증가 할 것이며 2030 년 이전에는 다른 배터리 시스템이 여전히 대규모 산업 발전이 어렵고 리튬 이온 배터리가 주류 기술 경로로 남아있을 것입니다.
리튬 배터리 음극재에서 경질 탄소 음극재가 차지하는 비율이 높지 않기 때문에 경질 탄소 음극재 재료에 대한 리튬의 당김은 적을 것입니다. 경질 탄소 음극재 300mah/g 용량, 3.2V 전압 플랫폼, 1GWh 리튬 배터리 계산에 따르면 약 1125톤의 경질 탄소 음극재가 소비되며, 2025년까지 약 35,000톤의 경질 탄소 음극재가 2025년까지 리튬 배터리 양극재 생산에 사용될 것으로 예상됩니다.
나트륨 배터리용 경질 탄소 음극재에 대한 수요 예측
경질 탄소 음극재의 특성과 나트륨 이온 배터리의 적용 시나리오: 최근 한 연구팀이 경질 탄소 음극 소재의 전기화학적 특성을 실험한 결과, 나트륨 이온 배터리의 음극 소재로 사용했을 때 369.8 mAh/g의 높은 비용량을 나타냈으며, 경질 탄소 음극 소재는 낮은 레독스 전위(0.1-1.0 V)를 가지고 있다는 사실을 밝혀냈습니다.
경질 탄소 음극재 전구체의 바이오매스 관련 전구체의 광범위한 사용으로 인해 배터리 음극재로 친환경적인 선택이 된 것도 경질 탄소 음극재입니다. 결론적으로 나트륨 이온 배터리 응용 분야에서 경질 탄소 음극재는 흑연에 비해 층 간격이 더 넓고 나트륨과 열적으로 안정적인 인터칼레이션 화합물을 형성할 수 있으며 연질 탄소와 비교하여 나트륨 저장 용량이 더 커서 나트륨 이온 배터리 전극, 나트륨 이온 축전기 전극 및 나트륨 기반 이중 이온 배터리 전극 등 나트륨 이온 배터리 관련 분야에서 더 나은 응용 시나리오를 가지고 있습니다.
에너지 밀도, 사이클 수명, 평균 전압, 안전성, 승수 성능, 고속 충전 성능 및 고온 및 저온 성능 측면에서 나트륨 이온 배터리, 리튬 철 인산염 배터리, 삼원계 배터리 및 납산 배터리의 특성을 비교 및 분석 한 결과 나트륨 이온 배터리는 전기 이륜차, 저속 전기 자동차, 에너지 저장 및 스타트-스톱의 응용 시나리오에서 좋은 전망을 가지고 있다고 믿습니다.
2023년부터 2025년까지 나트륨 배터리의 교체 비율이 5%, 15%, 25%라고 가정하면, 이에 해당하는 나트륨 배터리 설치 용량은 각각 9GWh, 33.7GWh, 72.5GWh입니다. 2023~2025년 나트륨 배터리용 경질 탄소 음극재 수요는 0.97만 톤, 3620만 톤, 779만 톤이 될 것으로 예상합니다.
경질 탄소 음극재 수요의 두 부분을 합산하면 2021년 경질 탄소 음극재 총 수요는 약 12,700,000톤, 2025년 경질 탄소 음극재 총 수요는 약 112,900,000톤으로 크게 성장하여 연평균 성장률이 72.8%에 달할 것으로 예상됩니다. 복합 성장률은 72.8%에 달합니다.
상위 10위권에서 더 많은 것을 확인하세요. 전 세계 나트륨 이온 배터리 회사, 실리콘 기반 양극.