Abstract:

The efficient recycling of valuable metals in spent lithium-ion batteries is the key to alleviate the contradiction between supply and demand of key metals. In this paper, the precursor of LiNi_1/3Mn_1/3Co_1/3O₂ ternary electrode material was prepared by leaching-sol-gel method using waste lithium-ion battery as raw material. The internal crystal structure and lattice morphology of electrode materials were analyzed and the electrochemical properties of the materials were also characterized. Results showed that the electrode material presented high sphericity and uniform particle size distribution, and the yield of -25μm particle size was 96.76% after calcination at 850℃ for 6h in CO₂ environment. Through the structural property analysis of the electrode material, it could be seen that the prepared material had a complete layered α-NaFeO₂ crystal structure, and the cation mixing degree was low, the layered structure was good, and the crystal structure of the material was clear lattice fringes and good crystallization degree. The electrochemical performance test results indicated that the prepared ternary materials exhibited excellent reversible discharge capacity and cyclic stability. The first discharge capacity of the electrode material reached 157.5mAh/g, and the reversible capacity remained at 141.6mAh/g after 160 cycles with a retention rate of 87%, which had the application prospect of commercial electrode materials.

Key words: lithium-ion batteries, cathode material, sol-gel method, electrochemical performance, cyclic stability

摘要：

废弃锂离子电池有价金属的高效循环利用是缓解我国关键金属供需矛盾的关键。本文以废弃锂离子电池电极材料为研究对象，通过浸出-溶胶-凝胶法制备LiNi_1/3Mn_1/3Co_1/3O₂三元电极材料前体，对基于电极材料的内部晶体结构和晶格形貌进行分析，并表征了材料的电化学性能。结果表明，在反应温度850℃、CO₂无氧环境下煅烧6h后，所制得的电极材料颗粒球形度高、粒度分布均匀，其中-25μm粒级产率为96.76%。制得的材料具备完整的层状α-NaFeO₂型晶体结构，且阳离子混排程度较低、层状结构良好，材料内部呈现出晶格条纹清晰且结晶程度良好的晶体结构。电化学性能测试结果表明，所制备的三元材料表现出优异的可逆放电容量和循环稳定性，首周放电容量达到157.5mAh/g，经160周循环周期后可逆容量仍保持为141.6mAh/g，保持率为87%，具备商品化电极材料的应用前景。

关键词: 锂离子电池, 正极材料, 溶胶-凝胶法, 电化学性能, 循环稳定性