Siloxane-modified ether based electrolyte boosting high-energy-density LiCoO2‖Li battery
To improve the interface compatibility between ether based electrolytes and high voltage cathodes,and increase the energy density to more than 350 W·h·kg-1 of lithium batteries,this study designed and synthesized an innovative ether-based electrolyte(Si-PEO)incorporating silane groups.Coin-type batteries were assembled for electrochemical performance and microstructure morphology analysis.The results show that ether chains are used to conduct lithium ions,and the silane chains contribute to improve the oxidative stability,which make the electrolyte have an ionic conductivity of 1.25×10-5 S·cm-1 at room temperature and a high electrochemical window(4.46 V).LiCoO2|Si-PEO|Li batteries maintain a discharge specific capacity of 160.12 mA·h·g-1 and a high capacity retention of 96.45%at 0.5 C at room temperature after 100 cycles.On the cycled LiCoO2 cathode surface,the particles are intact,with no accumulation of side reaction products,and a uniform cathode electrolyte interphase rich in inorganic components has been generated.The interphase can enable Si-PEO electrolyte and the cathode to have excellent thermal compatibility,thus improving the safety performance of LiCoO2‖Li batteries.
lithium metal batteriesether electrolytessilanecathode electrolyte interphasedischarge specific capacity
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