基于稳定化金属锂粉的硅电极预锂化性能探究

Research on prelithiation performance of silicon electrode based on stabilized metal lithium powder

为了解决锂离子电池首次充放电效率过低、不可逆容量损失会消耗大量电解液和正负极材料中脱出锂离子的问题,基于稳定化金属锂粉(SLMP)对硅电极进行预锂化,结合扫描电子显微镜(SEM)和X射线光电子能谱(XPS)对电极表面形貌及组成进行分析,探讨预锂化搁置时间及预锂化试剂用量对硅电极储锂性能的影响规律。研究表明,预锂化之后,减少了首次不可逆容量,提高了电极循环稳定性能。在预锂化搁置时间为36 h和SLMP用量为0.3 mg的条件下,硅电极的首次可逆容量可以达到3 444.9 mAh·g^(-1),经过60次充放电循环后,容量依然能保持1 247.2 mAh·g^(-1)。预锂化技术能补偿电池初始及循环过程中的不可逆容量损失,提高电池的容量及能量密度,显著延长电池的使用寿命。

In order to solve the problem of low initial charge and discharge efficiency and irreversible capacity loss of lithium-ion batteries,which consume a large amount of electrolyte and remove lithium ions from positive and negative electrode materials,the prelithiation of silicon electrodes using stabilized lithium metal powder(SLMP)was performed,and the surface morphology and composition of the electrodes were characterized using scanning electron microscopy(SEM)and X-ray photoelectron spectroscopy(XPS).The effects of prelithiation time and prelithiation reagent dosage on the lithium storage performance of silicon electrodes was investigated.The experiment indicated that the first irreversible capacity is reduced and the electrode cycling stability performance is improved after prelithiation.Under the conditions of 36 hours of prelithiation and 0.3 mg of SLMP dosage,the first reversible capacity of the silicon electrode can reach 3444.9 mAh·g^(-1).After 60 charging and discharging cycles,the capacity can still maintain 1247.2 mAh·g^(-1).Prelithiation technology can compensate for irreversible capacity loss during the initial and cycling processes of batteries,improve their capacity and energy density,and significantly extend their long-term life.