0 引言
1 实验部分
1.1 试剂与仪器
1.2 化合物DSMCN的合成
Fig. 1 1H-NMR (a), 13C-NMR (b), and 29Si-NMR (c) spectra of DSMCN图1 DSMCN的1H-NMR(a)、13C-NMR(b)和29Si-NMR(c)谱图 |
1.3 NCM811电极片的制备
1.4 电解液的配置
2 结果与讨论
2.1 合成路线
Fig. 2 Synthesis route of DSMCN图2 DSMCN的合成路线 |
2.2 DSMCN的氧化电位
Fig. 3 (a) HOMO energy levels of EC, DMC, EMC, and DSMCN obtained from DFT calculations; (b) LSV curves of different electrolytes图3 (a)DFT计算得到的EC、DMC、EMC、DSMCN的HOMO能级;(b)不同电解液的LSV曲线 |
Fig. 4 CV curves of NCM811/Li half-cells with base electrolyte (a) and electrolyte containing 2% DSMCN (b)图4 基础电解液(a)和含有2% DSMCN电解液(b)的NCM811/Li半电池的CV曲线 |
2.3 电池循环性能
Fig. 5 (a) Cycling curves and coulombic efficiency of NCM811/Li cells under different conditions: (a) base electrolyte and electrolytes containing 1%, 2%, and 5% DSMCN at room temperature; (b) base electrolyte and electrolyte containing 2% DSMCN at 55 ℃; (c) base electrolyte and electrolyte containing 2% DSMCN after 500 cycles at room temperature图5 不同条件下的NCM811/Li电池的循环曲线和库伦效率:(a)常温下基础电解液和1%、2%、5% DSMCN电解液;(b)55 ℃下基础电解液和2% DSMCN电解液;(c)常温下基础电解液和2% DSMCN电解液循环500圈 |
Fig. 6 Rate performance of base electrolyte and electrolyte containing 2% DSMCN in NCM811/Li half cell图6 基础电解液和2% DSMCN电解液的NCM811/Li半电池的倍率性能 |
2.4 交流阻抗分析
Fig. 7 Impedance spectra of NCM811/Li cells with base electrolyte and electrolyte containing 2% DSMCN after three cycles of activation at 0.1 C (a) and after 200 cycles at 1 C (b)图7 基础电解液和2% DMSCN电解液的NCM811/Li电池在0.1 C活化3圈后(a)和1 C循环200圈后(b)的阻抗图 |
2.5 NCM811电极的容量-电压曲线
Fig. 8 Charge-discharge curves of NCM811/Li cells at different cycle numbers in base electrolyte (a) and electrolyte containing 2% DSMCN (b)图8 NCM811/Li电池在基础电解液(a)和2% DSMCN电解液(b)中不同循环圈数的充放电曲线 |
2.6 电极界面形貌与组成
Fig. 9 SEM images after 500 cycles of the NCM811 electrodes: (a, b) base electrolyte; (c, d) electrolyte containing 2% DSMCN图9 NCM811极片循环500圈后SEM扫描极片的形貌:(a、b)基础电解液;(c、d)2% DSMCN电解液 |
2.7 电极界面材料结构分析
Fig. 10 (a) XRD patterns of NCM811 electrodes before and after 100 cycles; (b, c) localized enlargements图10 (a)循环前及循环100圈后的NCM811极片的XRD图;(b、c)局部放大图 |