Reasearch On The Recovery And Reuse Of Lithium Trifluoromethylsulfonimide And PEO In PEO Electrolyte

Polyethylene oxide（PEO）polymer electrolytes have attracted attention due to their excellent thermal stability,simple preparation,and stable Linegative electrode interface.In recent years,significant progress has been made in the optimization design based on this system.In order to promote the application of PEO-LiTFSI based electrolytes,it is equally important to consider performance improvement while considering the high value recycling of materials,among which LiTFSI is expensive and has high recovery value.Therefore,this article explores a pyrolysis process for recovering LiTFSI from PEO-LiTFSI electrolyte,and proposes two optimization strategies based on this process to improve the recovery rate of LiTFSI.The product recovered by those processes have high purity and has reuse value.（1）The initial decomposition temperature of PEO is lower than that of LiTFSI,so LiTFSI can be individually recovered by pyrolysis process.Place the waste electrolyte membrane in the N₂tube furnace at 340°C for 3 h,and recover LiTFSI from the pyrolysis substrate through liquid phase treatment,with a recovery rate of 55%.（2）Introducing Lewis acid catalyst to optimize pyrolysis conditions and improving the recovery rate of LiTFSI.Mix the waste electrolyte membrane with an appropriate amount of Sn F₂/LiPF₆composite catalyst and place it in the N₂tube furnace at 280°C for 3 h,then recover LiTFSI from the pyrolysis substrate through liquid phase treatment,with a recovery rate of 70%.（3）In order to reduce greenhouse gas emissions during pyrolysis,PEO was recoceryed.Ethylene glycol achieves primary separation of PEO and LiTFSI,achieving the recovery of PEO.After primary separation,the separation material rich in LiTFSI is placed in the N₂tube furnace at 320°C for 3 h,and the pyrolysis substrate is treated in liquid phase to recover LiTFSI.The recovery rate was 96%for PEO and 65%for LiTFSI.