High safety lithium-ion battery enabled by a thermal-induced shutdown separator

The market of lithium-ion batteries (LIBs) is growing explosively especially due to the wide application of electric vehicles. However, there are still safety concerns existing with EVs under thermal/electrochemical abuse con-ditions. Improving the safety of the battery without sacrificing battery performance is still a major industrial/scientific challenge. Herein, a shutdown functional high-density polyethylene (HDPE) wax@boehmite (gamma-AlOOH, AO)/PE composite separator is proposed. The HDPE@AO coating layer could be preferentially melted and infuse to block the pores of PE matrix, which shuts down the lithium-ion transportation at about 130 degrees C significantly improving the safety of the LIBs. Furthermore, it could also restrain self-discharge behavior and promote the long-term cycling performance. The HDPE wax@AO/PE separator, which could be easily mass produced, holds great promise for large scale application in electric vehicles and other fields.