锂离子电池用新型LixAl@C纳米复合负极材料的电化学过程研究及高性能锂离子电池电极体系的构建

锂离子电池能量密度仍在120 Wh/kg左右徘徊，难以满足社会高速发展的需要。V2O5等无锂正极材料制备容易，价格低廉，比容量高，电化学性能优良，极具提高锂离子电池能量密度的潜力。但是，其需要匹配高性能有锂负极构成卓越的电池体系才能发挥优良性能。LixAl比容量高，是较佳的匹配负极。据此，本课题提出以碳包覆纳米化 的LixAl合金，去除LixAl在脱、嵌锂过程中体积变化带来的弊端，形成纳米LixAl@C复合负极材料，与V2O5等无锂正极材料构成新型电极系统。对纳米LixAl@C复合材料的制备方法与结构之间的内部关系，复合材料的电化学性能与结构之间的关系等科学问题开展研究，以及对无锂型正极材料与纳米LixAl@C构成电极体系的匹配、电压、寿命等问题进行深入研究，以获得完善的纳米LixAl@C复合负极材料制备方法、该材料的储能机理和新型锂离子电池电极体系原型。

The energy density of lithium ion battery is still hovering at about 120 Wh/kg, difficult to meet the needs of the rapid development of society. V2O5 and other cathode materiales have highly potential for improving energy density because of easy preparation, low price, high capacity and excellent electrochemical performance. However, they need match with high performance anode with lithium supply. LixAl, with high capacity, is a better match anode. In this projects, a new electrode system were constructed and studied with carbon coated nano LixAl alloy (LixAl@C) as anode, V2O5 etc as cathodes. The structure of LixAl@C can eliminate the disadvantage of volume change during lithium insertion and extraction. The internal relationship between the preparation method and the structure of LixAl@C composite material, electrochemical properties and structure of composite materials and the voltage, cycle life, match of the eletrodes of the new system will be intensively discussed. The perfect preparation method and energy storage mechanism of LixAl@C composite, and the new lithium ion battery electrode system　protype will be obtained.