Study on the Novel Anode for Anode for Advanced Lithium Secondary Batteries

超细SnSb_2<0.14>、SnO和SiO粉末作为嵌锂主体在第一次循环中表现出较高的不可逆性。研究了含锡主体与Li_<2.6>Co_<0.4>N的组合作为锂离子电池复合负极。新的阳极系统降低或消除了首次不可逆容量，提高了循环性能，首次锂化容量约为1000 mAh。90 mAh/g，<2.6><0.4>其脱锂容量约为100 mAh/g。900 mAh/g，主要在相对于Li的1 V的电位平台下。首次循环后，<2.6>LiCoN<0.4>相结构由晶态转变为非晶态，但仍能保持800 mAh/g以上的循环容量。对于超细SnSb_x、SnO和SiO，尽管其可逆容量在550 ~ 1300 mAh/g之间，但首次循环效率一般低于65%。当将两种不同的主体混合以形成复合电极时，第一循环效率变得可通过控制两种主体的比率来调节。由于Li_<2.6>Co_<0.4>N在电极中的分散性减小了其体积膨胀，从而消除了体积变化效应，因此复合电极的循环稳定性优于合金和氧化物。该复合电极不仅可用于液体电解质，而且可用于固体聚合物电解质。

Ultrafine SnSb_<0.14>, SnO and SiO powders as hosts for lithium insertion show high irreversibility in the first cycle. A combination of the tin-containing hosts with Li_<2.6>Co_<0.4>N has been examined for composite anodes in lithium ion batteries. The new anode systems reduce or eliminate the first irreversible capacity and improve the cycle performances.The first lithiation capacity is ca. 90 mAh/g for Li_<2.6>Co_<0.4>N electrode and its delithiation capacity is ca. 900 mAh/g, mostly at the potential plateau of 1 V vs. Li. After the first cycle, Li_<2.6>Co_<0.4>N phase structure changes from crystalline to amorphous state, but a cycle capacity over 800 mAh/g can still be kept. For ultrafine SnSb_x, SnO and SiO, the first cycle efficiency is generally below 65 % in spite of their high reversible capacities from 550 to 1300 mAh/g. When the two different hosts are mixed to form a composite electrode, the first cycle efficiency becomes adjustable by controlling the ratio of the two hosts. The composite electrodes show a better cycle stability than the alloy and oxides, because a dispersion of Li_<2.6>Co_<0.4>N in the electrodes alleviates the volume change effect due to its small volume expansion. The composite electrodes can be used not only in liquid electrolytes, but also in solid polymer electrolytes.