Interfacial regulation of Li-ion battery at high voltage operation through a multifunctional copolymer additive

Abstract

The reactivity at the electrode/electrolyte interface poses a critical challenge for high-voltage materials in next-generation lithium-ion batteries. In fact, elevated potentials accelerate parasitic side reactions leading to the oxidation of the conventional liquid electrolytes resulting in the formation of unstable interphases, and continuous electrolyte decomposition. These interfacial instabilities degrade capacity retention, reduce coulombic efficiency, and compromise the long-term safety and performance of the battery. This study explores the use of a novel polymer-based additive designed to regulate the electrode/electrolyte interphase and controlling lithium stripping/plating at the anode surface. By minimizing electrolyte decomposition, the additive reduces undesirable reactions and continuous electrolyte consumption. The presented results demonstrate that even at low concentration, this additive significantly reduces parasitic reactions and enhances interfacial stability at both anode and cathode surfaces. Resulting in an improved coulombic efficiency, higher discharge capacity, and enhanced capacity retention over the 200 cycles. • A new copolymer additive was successively prepared. • This additive enables high coulombic efficiency and stable lithium stripping/plating. • Stabilization of electrode/electrolyte interfaces was demonstrated. • Additive reduces electrolyte decomposition and accumulation of carbonate species.