Effect of halogen-nitrate heterogeneous additives in carbonate-ether mixed electrolytes on inhibiting the growth of Li dendrites

Abstract

Li metal is recognized as the most promising anode for Li metal batteries due to its high energy density. However, Li dendritic growth is one of the critical obstacles as the presence of this formation may lead to short circuits which will result in the fatal safety hazards like fire and explosion. Developing electrolytes which stabilize the solid electrolyte interface (SEI) film on Li/electrolyte interface to inhibit the Li dendritic formation is still challenging. Among the different electrolytes, few are reported based on LiNO3-carbonated electrolyte because of the low solubility of LiNO3 in carbonated solution. Here, the new advanced electrolyte based on halogen ions (XC1—, Br—, I—) dissolved in a mixture of vinyl carbonate, dimethyl carbonate and dimethyl ether (EC:DMC:DME) on inhibiting Li dendrites was investigated systematically. The highly smooth surface of Li metal could be obtained by adopting the LiBr-LiNO3 electrolytes. The formed stable and homogeneous SEI film fundamentally decreases the nucleation sites for dendritic Li and establishes ideal matrix for the even Li deposition. The Li metal thus shows improved cycling in LiBr-LiNO3 mixed electrolyte which may be the crucial for inhibit dendrite growth intrinsically.