Adjusting Interfacial Reactions for Achieving Highly Stable Operation in Lithium Metal Batteries

Abstract

Lithium-metal batteries (LMBs) are considered a promising candidate for next-generation high energy-density batteries. However, the unstable interface and dendrite growth severely restrict the commercial applications of lithium metal anodes. Here, we pioneeringly propose an electrolyte that consists of a simple cyclic vinylethylene carbonate (VEC) solvent and LiTFSI salt, enabling LMBs with high performance in the aspects of long cycle life and high Coulombic efficiency (CE). Jointed experimental and DFT calculations demonstrate that the favorable reduction of the VEC induces a uniform distribution of elastic organic polymer molecules at the anode surface with high mechanical strength, which reinforces the inorganic Li 2 CO 3 and LiF underneath and maintains the integrality of the solid electrolyte interphase (SEI) film. The inorganic compounds display a high Li ion diffusion coefficient, surface energy, and Young's modulus (10.71 GPa), which effectively accelerate the interfacial kinetics and homogenize the metallic Li deposition. In addition, the low solvation energy of the Li ions in the VEC effectively improves the desolvation process compared to traditional electrolytes. Thus, this organic/inorganic laminated SEI film enables an excellent CE of 98% after 450 cycles and highly stable cycling over 3000 h. This work provides a cost-effective proposal, paving the way for industrial applications of cyclic carbonate-based electrolytes in LMBs.

Engineering the Interfacial Compatibility of a Small-Molecule Quinone Cathode toward Stable Quasi-Solid-State Lithium-Organic Batteries

“…The development of high-energy-density rechargeable batteries is becoming more and more urgent as the need for advanced energy storage devices continuously increases. Lithium metal batteries (LMBs) are known for their energy density due to the high theoretical specific capacity (3860 mAh g –1 ) of the lithium metal anode. − However, the commercialization of LMBs is hampered due to dangerous accidents caused by the use of an all-liquid electrolyte and unsatisfactory electrode compatibility. In this regard, customizing solid-state electrolytes with high interfacial compatibility is deemed an optimal strategy due to their nonflammable features. − Typically, inorganic electrolytes and polymer electrolytes are the main types of solid electrolytes.…”