纳米钴基氧化物锂离子电池负极材料的研究

Nano-sized Cobalt-based Oxides as Negative Electrode for Lithium-ion Batteries

采用流变相法合成Co3 O4 ,CoB1.3 6 O2 .8,CoB0 .5Al0 .1O1.5样品 ,并研究其作为锂离子电池负极材料的电化学性能 .当电池在 0 .0 1～ 3.0 0V的电压范围之间循环时 ,Li/Co3 O4 电池表现出最好的充放电性能 :循环 30周后 ,可逆比容量仍能保持为初始比容量 (931mAh/g)的 95 % .掺杂了B ,Al材料 ,其可逆比容量与未掺杂的相比明显降低 ,而且第 1周可逆容量随掺杂的B、Al量的增加而减少 .通过异位XRD方法研究了不同充放电态Co3 O4 电极材料结构的变化 .结果表明 ,Co3 O4 电极在充放电过程中与Li的反应机理不同于传统的过渡金属与Li的反应机理 ,即非Li+ 的嵌入 /脱出或合金的形成 ,而是Co3 O4 的可逆还原氧化以及Li2

Nanosized cobalt-based oxide (Co 3O 4, CoB 1.36 O 2.8 and CoB 0.5 Al 0.1 O 1.5 ) samples were prepared by rheological phase method and were tested as anodes in secondary lithium batteries. The cells were cycled between 0.01V and 3.00 V. The best electrochemical performance was obtained from the Li/Co 3O 4 cell, which retained 95% of its initial capacity (931 mAh/g) after 30 cycles. The doping of B, Al reduced the reversible capacity during the first discharge/charge cycle, and the quantity of reversible capacity reduced with B, A1 increasing. The modifying structures at difference charge and discharge states were investigated by ex situ XRD method. The results indicated which Li reacting from the classical Li insertion/deinsertion or Li-alloying processe, involves the formation/decomposition process of Li 2O and the reduction and oxidation of coblat oxides.