Improved cycling performances with high sulfur loading enabled by pre-treating lithium anode

Lithium nitrate (LiNO3) is reported as an effective additive to protect lithium anode in rechargeable lithium-sulfur battery. However, for its strong oxidation, cells containing LiNO3 still suffer from safety problems and poor cycle performance since LiNO3 can be reduced on cathode to form some irreversible products. In this study, a facile and effective method to pre-passivate lithium anode is proposed by simply immersing lithium plates in LiNO3 solution. The electrochemical properties show that the pretreatment is favorable for the construction of a protection layer on the surface of lithium anode. Cells with pretreated lithium show the coulombic efficiency of 80.6 % in the first cycle and 87.2 % after 100 cycles, far higher than the one with pure lithium. The discharge capacity is retained at 702 mA h g(-1) after 100 cycles, and the result is better than those directly adding LiNO3 in electrolyte. It is believed that these improvements result from the high stability of surface film during the charge and discharge process, which can stabilize the structure of anode and suppress the shuttle effect.