At present, the form of A-M ‘type intermetallic compounds is widely used to buffer the volume change of alloy anode materials [11], where A is Al, Sn, Si and Sb and other active lithium storage elements, and M’ is an element that cannot form an alloy with lithium. The first reversible capacity of SiO0. The research and application of anode materials for high-capacity lithium-ion batteries have become the key to improving battery performance. The thin film negative electrode is tightly coupled with the current collector, reducing the influence of the binder on the graphite electrode for arc furnace electrode performance. [11] prepared the Ag-doped Sn-Zr film by electron beam evaporation. Y
. The crystal structures formed by different elements vary greatly. [12] show that increasing the content of the inert element Cu can increase the ring stability of the alloy.5 μm reached 485 mAh / g, which was close to the theoretical capacity (543 mAh / g) when AlLi was produced, but the capacity retention rate after 2 cycles 30%. [19] prepared aluminum thin films with different thicknesses by thermal evaporation method, and used lithium metal as the counter electrode to conduct constant current charge and discharge test. Among them, Mg2Si has been studied more [22].
In this way, when the compound is formed, the structure of the component crystals will be reconstructed, accompanied by large volume expansion; at the same time, in the crystalline material, the formation of intermetallic compounds will also cause uneven volume changes in the two-phase boundary region, Cause cracking or pulverization of active particles.
Most metal elements that can form alloys with lithium will form a lithium-containing intermetallic compound LixMy when intercalation and deintercalation reactions occur. Among various types of alloy anode materials, thin film materials occupy an important position.6Sn48. E. After 50 cycles, CaSi2 with a particle size of 30 μm and a reversible capacity of 150 mAh / g; and CaSi2 with a particle size of 1-3 μm and a reversible capacity of 220 mAh / g. When lithium is intercalated, a clear voltage platform appears at 0.X.
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