The anode material is one of the key factors determining the performance of lithium-ion batteries. Currently, the anode materials used in commercial lithium-ion batteries mainly include: ① graphite-based carbon materials, which are divided into natural graphite and artificial graphite; ② disordered carbon materials, including hard carbon and soft carbon; ③ lithium titanate materials; ④ silicon-based materials, which are mainly divided into carbon-coated silicon suboxide composite materials, nano-silicon carbon composite materials, and amorphous silicon alloys.
With rapid economic development and ever-changing technology, the widespread use of electronic products has reached an all-time high. The development of electric vehicles, a crucial application area, has driven improvements in battery performance while also placing higher demands on batteries, including increased energy density and extended cycle life. Current research on anode materials focuses on novel carbon materials, silicon-based materials, tin-based materials, and their oxide anode materials.
Novel carbon materials are those that are different from traditional carbon materials. Currently, graphite, a traditional carbon material, is widely used commercially as the anode material for lithium-ion batteries. However, its theoretical capacity is relatively low and increasingly fails to meet the development needs of lithium-ion batteries. Novel carbon materials, such as carbon nanotubes and graphene, have great potential in lithium-ion battery applications due to their unique one-dimensional and two-dimensional flexible structures and excellent thermal and electrical conductivity.
Compared to other lithium-ion battery anode materials, silicon-based anode materials have a very high specific capacity. However, the high expansion rate of silicon during charging and discharging limits its application in anode materials. Anode materials prepared by combining silicon with other materials can overcome this defect to some extent.
Metallic tin and lithium can undergo an alloying reaction to form a variety of intermetallic compounds, LixSn (x=0.4, 1.0, 2.33, 2.5, 2.6, 3.5, 4.4), which is a promising anode material for lithium-ion batteries.
