高温相LiCoO2纳米片阵列的低温熔盐制备及其倍率和循环性能研究

LiCoO2 is a commercial star material in lithium battery cathode materials，which has advantages of high working voltage platform, stable discharge, high specific energy and good cycle performance. However, experiments show it still faces capacity fading and poor cycle performance under high rate charge-discharge. From the perspective of structural dynamics，we intends to design LiCoO2 structure with high rate and cycle performance at high charge-discharge rate in this project. By low-temperature molten salt method (~200°C), the hexagonal layered high-temperature phase LiCoO2 nanosheet array would be prepared; Meanwhile, the followings would be investigated: (1) Controllable preparation of high-temperature phase LiCoO2 nanosheet array structures; (2) Effect of different molten salt conditions on the crystallinity and morphology of high-temperature phase LiCoO2; (3) Influence rules among Array structure parameter - molten salt reaction conditions - electrochemical properties. 3、Further, by reviewing the experimental results, we would reveal the influence mechanism of electrode charge-discharge dynamic process and provide reference for the design and low energy consumption preparation and high rate application of other lithium battery cathode materials.

LiCoO2是锂电池正极材料中的商业化多年的明星材料，具有工作电压高、放电平稳、比能量高、循环性能好等优点，然而实验表明，在大倍率充放电下，其仍然面临容量大幅衰减，循环性差的问题。本项目拟从动力学的角度对LiCoO2进行结构设计，使其在大倍率充放电下仍然保持高的倍率和循环性能。通过低温熔盐法(~200℃)制备六方层状高温相的LiCoO2纳米片阵列，系统性的研究:(1)高温相LiCoO2纳米片阵列结构的可控制备，(2)熔盐反应中不同熔盐条件对生成高温相钴酸锂结晶性、形貌的影响；(3)阵列结构-熔盐反应条件-电化学性能之间的影响规律。总结工作，揭示LiCoO2纳米片阵列电极充放电过程动力学的影响机制，进而对其他锂电池正极材料结构的设计、低能耗制备、和大倍率充放电下的使用提供借鉴。

为了提高钴酸锂正极材料的电化学性能，本项目从动力学的角度对LiCoO2进行结构设计，通过低温熔盐法制备六方层状高温相的LiCoO2纳米片阵列，使其在大倍率充放电下仍然保持高的倍率和循环性能。具体完成的研究内容及结果包括：(1)钴酸锂纳米片阵列结构的可控制备；(2)熔盐反应中不同熔盐条件对生成高温相钴酸锂结晶性、形貌的影响；钴酸锂纳米片阵列电化学性能的探究；(3)其它电化学储能体系和材料的探究。