正硅酸乙酯对高电压镍锰酸锂基全电池电化学性能的影响

为了提高镍锰酸锂全电池的电化学性能,本文采用物理混合的方法在负极浆料中加入正硅酸乙酯(TEOS),并按m(TEOS)∶m(石墨)=0∶100、5∶100、10∶100、16∶100、20∶100的比例进行搅拌混合。 以镍锰酸锂为正极,石墨为负极,组装成502030型软包装锂离子电池,并对该电池进行恒流充放电和内阻等测试。 测试结果显示,0TEOS(m(TEOS)∶m(石墨)=0∶100)样品的电池内阻为159 mΩ,循环200圈后,容量保持率为52.6%,放电比容量为46 mA·h/g;16TEOS(m(TEOS)∶m(石墨)=16∶100)样品的电池为105 mΩ,65.7%和62.9 mA·h/g。 实验结果表明:通过物理混合的方法在负极浆料中加入TEOS,有利于在负极表面形成结构稳定的人工固体电解质膜(SEI膜),提高镍锰酸锂材料的循环和倍率性能。

Effects of Ethyl Orthosilicate on the Electrochemical Performance of High-Voltage Lithium Nickel Manganese Oxide-Based Full-Cell

In order to improve the electrochemical performance of LiNi_0.5Mn_1.5O₄ lithium ion batteries, a physical mixing method was used to add ethyl orthosilicate (TEOS) to the negative electrode slurry with the mass ratios of TEOS to graphite of 0∶100, 5∶100, 10∶100, 16∶100 and 20∶100. A 502030-type flexible packaging lithium-ion battery was assembled by using LiNi_0.5Mn_1.5O₄ as the positive electrode and graphite as the negative electrode. The battery was tested for constant current charge and discharge and internal resistance. The test results show that the internal resistance of the 0TEOS(m(TEOS)∶m(graphite)=0∶100) and 16TEOS(m(TEOS)∶m(graphite)=16∶100) batteries are 159 mΩ and 105 mΩ, respectively. After 200 cycles, the capacity retention rates are 52.6% and 65.7%, and the specific discharge capacities are 46 mA·h/g and 62.9 mA·h/g, respectively. The addition of TEOS to the negative electrode slurry through a physical mixing method is beneficial to the formation of a structurally stable artificial solid electrolyte interface(SEI) film on the surface of the negative electrode, and improves the cycling and rate performance of LiNi_0.5Mn_1.5O₄.