The effects of LiBOB additive for stable SEI formation of PP13TFSI-organic mixed electrolyte in lithium ion batteries

► LiBOB as the additive of SEI formation. ► LiBOB containing mixed electrolyte shows well thermal stability and safety. ► LiBOB improves the electrochemical performance of PP13TFSI-organic mixture. A safe electrolyte system is prepared from N-methyl- N-propylpiperidinium bis (trifluoromethanesulfonyl) imide (PP13TFSI), organic electrolyte (1 mol L −1 LiPF 6/EC-DEC) and lithium bis (oxalato) borate (LiBOB). The additive of LiBOB enhances the stability of interface between electrolyte and anode. The LiBOB-containing mixed electrolytes show non-flammability and good compatibility with active materials. The performance of anode for lithium ion battery is successfully improved by LiBOB-containing mixed electrolytes, which shows 200 mA h g −1 reversible capacities at 0.3 C rate. The ionic conductivity and the lithium ion transference number in LiBOB-containing mixed electrolytes system also suits to application for lithium ion battery.