电池型电容器的正极结构设计与性能
Structure design and performance of cathode for battery-type capacitor
田洪松 1刘富亮 1周雄 1袁东 1石斌 1袁再芳1
作者信息
- 1. 贵州梅岭电源有限公司,特种化学电源全国重点实验室,贵州 遵义 563003
- 折叠
摘要
电池型电容器正极材料在涂覆干燥时,会因表面张力导致出现电极界面不稳定、极片电阻率偏大及孔隙率分布不均匀等问题.以高电压钴酸锂(LiCoO2)为正极材料,采用多层涂覆技术对LiCoO2 正极片进行厚度梯度设计.控制双层涂覆极片的总厚度为 30 μm,调节双层极片的厚度梯度分布,实现极片上下层孔隙率的差异化分布,构造Li+快速传输通道,减小离子扩散阻力、减缓容量衰减.与具有各向异性和高层间距的硬碳(HC)负极组装成软包装电池型电容器,进行电化学性能测试.双层电极LH-18(第一层涂覆厚度为 18 μm)首次循环的库仑效率达到 80.85%,比单层电极(LH-30)高 6.27 个百分点.在 2.5～4.2 V循环,20.00 C的放电容量为 1.00 C时的 81.82%,1.00 C充放电 100%放电深度(DOD)循环 3 509次后,容量保持率仍有 80%,循环次数是单层电极(LH-30)的 2.27 倍.
Abstract
When the cathode material of battery-type capacitors is coated and dried,the surface tension will lead to the instability of the electrode interface,the large resistivity of the pole piece and the uneven distribution of porosity.High-voltage lithium cobalt oxide(LiCoO2)is used as the cathode material,the thickness gradient design of the LiCoO2 cathode plate is carried out by using multi-layer coating technology.By controlling the total thickness of the double-layer coated electrode plates to 30 μm,the thickness gradient distribution between the double-layer electrode plates is adjusted,the differential distribution of porosity between the upper and lower layers of the electrode plates is realized,the rapid transmission channel of Li+is constructed to reduce ion diffusion resistance and slow capacity attenuation.A pouch battery-type capacitor is assembled with a hard carbon(HC)anode with anisotropy and high space,its electrochemical performance is tested.The Coulombic efficiency in the initial cycle of the two-layer electrodes LH-18(the thickness of the first layer is 18 μm)reaches 80.85%,which is 6.27 percentage points higher than the single-layer electrode(LH-30).When cycled in 2.5-4.2 V,the discharge capacity at 20.00 C is 81.82%of that at 1.00 C.After 3 509 cycles of 100%depth of discharge(DOD)at 1.00 C,the capacity retention rate is still 80%,the cycle number is 2.27 times than that of the single-layer electrode(LH-30).
关键词
电池型电容器/钴酸锂(LiCoO2)/硬碳/多层涂覆Key words
battery-type capacitor/lithium cobalt oxide(LiCoO2)/hard carbon/multi-layer coating引用本文复制引用
出版年
2024
国家科技期刊平台
NSTL
万方数据