Anode materials are mainly divided into carbon-based materials and non-carbon-based materials. Carbon-based materials are mainly graphite-based anode materials. Among non-carbon-based materials, silicon-based anode materials are currently more concerned.
At present, graphite-based anode materials are the mainstream anode materials, which are mainly divided into artificial graphite and natural graphite.
Natural graphite is derived from mines, mined from mines and made through flotation, spheroidization, and surface coating; artificial graphite is derived from coal and petrochemical by-products, which are coal tar pitch or residual oil, by-products of petroleum or coal chemical industry. The raw material is made into needle coke by delayed coking, and is made by granulation and graphitization.
As the sales of new energy vehicles and power batteries continue to grow, the demand for anode materials is still strong, and the anode materials are mainly artificial graphite and natural graphite. Among them, artificial graphite accounts for more than 80%.
Natural graphite has different particle sizes and wide particle size distribution. The mined natural graphite ore needs to go through flotation, spheroidization, surface coating and other steps to make natural graphite negative electrode material, while artificial graphite has a shape and particle size distribution. more consistent.
Natural graphite has high capacity, high compaction density and relatively cheap price, but due to different particle sizes, many surface defects, poor compatibility with electrolytes, and more side reactions; and the performance of artificial graphite It is more balanced, the cycle performance is good, and the compatibility with the electrolyte is also better, so the price will be more expensive.
Although natural graphite has the advantages of cost and specific capacity, its cycle life is low and its consistency is lower than that of artificial graphite. Compared with natural modified graphite, artificial graphite technology is more mature.
Natural graphite is mainly used for small lithium batteries and lithium batteries for general-purpose electronic products, while artificial graphite is widely used in automotive power batteries and medium-sized batteries by virtue of its outstanding cycle performance, high-rate charge-discharge efficiency, and electrolyte compatibility. high-end electronic products.
At present, with the continuous expansion of the power battery market, the comprehensive requirements for factors such as material cost, processing performance, energy density, cycle life, and fast charging rate have increased, helping artificial graphite to become the most important material in anode materials.
There is no clear distinction between artificial graphite and natural graphite technical routes, and it is more based on the choice of their own technical routes.
The structure of natural graphite determines that the volume of graphite changes greatly during the lithium intercalation and deintercalation process, resulting in the destruction of the graphite layer structure, which in turn causes a large irreversible capacity loss and a dramatic deterioration of the cycle performance.
Therefore, when natural graphite is used, it often focuses on its modification research to improve its own structural shortcomings and improve battery performance.
It is expected that in the next few years, the proportion of artificial graphite will continue to rise due to the application of new energy vehicles.
However, due to its excellent characteristics of natural graphite, for example, in terms of expanded graphite, artificial graphite cannot replace natural graphite; and the current composite graphite route of artificial graphite doped with natural graphite has also gradually increased the demand for natural graphite, and the future economic development. China Natural Graphite still has its own irreplaceable market.
