Why do lithium-ion batteries use silicon carbon as a negative electrode material? In recent years, my country’s lithium-ion battery industry has developed rapidly, and the global market share has continued to increase. Compared with graphite anodes, silicon carbon anodes have higher mass energy density and volumetric energy density. The mass energy density of lithium-ion batteries using silicon anode materials can be improved. Above 8%, the volumetric energy density can be increased by more than 10%. Therefore, silicon anode materials will have very broad application prospects.
Why do lithium-ion batteries use silicon carbon as the negative electrode material?
Silicon is the lithium-ion battery anode material with the highest specific capacity (4200mAh/g) discovered so far by humans, and it is a kind of anode material with the most potential. The problems of silicon anode materials include low cycle life, large volume changes, and continuous production of SEI films. Silicon-carbon lithium-ion battery anode materials can effectively improve these problems. Therefore, silicon-carbon anode materials are undoubtedly the development focus of anode materials in the future.
The mass specific capacity of silicon material can reach up to 4200mAh/g, which is much larger than the 372mAh/g of carbon material. It is currently the material with the highest theoretical specific capacity known to be used as a negative electrode material. In addition, silicon materials are environmentally friendly, rich in reserves, and low in cost. However, the problems of silicon anode materials include low cycle life, large volume changes, and continuous production of SEI films. Silicon-carbon lithium battery anode materials can effectively improve these problems. Therefore, silicon-carbon anode materials are undoubtedly the development focus of anode materials in the future.
Some foreign companies have achieved mass production of silicon carbon anode materials. Domestic companies have been relatively slow in the industrialization of silicon carbon anodes. Shanshan Co., Ltd., Jiangxi Zichen, and Shenzhen Beiterui have already deployed the production of silicon-carbon anode materials. At present, they have launched several silicon-carbon anode materials with certain production capacity.
With the development of battery electrode materials, lithium-ion battery technology has developed rapidly. At present, lithium-cobalt batteries have been extended to battery systems such as ternary systems, lithium manganese oxide, lithium iron phosphate, and silicon carbon anodes. The new silicon-carbon anode lithium ion battery breaks through the inherent limitations of graphite as a negative electrode, and its performance is significantly better than traditional lithium ion batteries. It has become one of the most promising energy storage batteries.
Because the silicon-carbon anode material has a high lithium insertion potential, the formation and precipitation of lithium metal are avoided during the sintering process, and because the equilibrium potential is higher than the reduction potential of most electrolyte solvents, it will not interact with the electrolyte and in the solid-liquid No passivation film is formed on the interface, many side reactions are avoided, safety is greatly improved, and safety and stability are the most important indicators in the sintering process of lithium materials.
The total output of silicon carbon anode materials is still less than 1% of lithium battery anode materials. However, with the expansion of major anode companies and the rise of new companies, it is expected that silicon carbon materials will officially enter the market in large quantities by the end of 2019. Silicon-carbon anode materials are the most promising anode materials for lithium batteries in the future. It can be seen how large the market capacity of silicon-carbon anode materials is, which also explains why many companies and research units are currently deploying silicon-carbon anode materials.
Summary: Lithium battery anode materials are currently at the most critical link in the lithium-ion battery industry. Anode materials account for 25% to 28% of the total cost of lithium batteries. As a new type of lithium ion battery anode material, silicon carbon anode is more efficient than the current graphite anode in improving battery energy density. The application prospects of silicon-carbon anode materials are getting brighter and brighter. In the future, silicon-carbon anode materials are likely to become the leader in anode materials.
