Electrolyte Design Principles for Fast Charging in High-Voltage Lithium Batteries

Enhancing charging rates is pivotal for electrified technologies, motivating the development of “charge-and-go” energy storage systems. High-voltage batteries are particularly attractive as the energy output scales with both voltage and capacity. However, fast-charging at high voltages is fundamentally constrained by sluggish Li⁺ transport and interfacial degradation. Rational electrolyte design is therfore a critical strategy to overcome these limitations. In this Review, we examine the key mechanistic origins of these limitations and summarize electrolyte-driven solutions for high-voltage, fast-charging lithium batteries. We summarize recent advances across five strategies, including fluorinated electrolytes, superconcentrated and localized high-concentration electrolytes, competitive and cooperative coordination, electron-donor molecular design, and asymmetric molecular architectures. We further elucidate the correlation between operating voltage and ionic conductivity in emerging high-voltage fast-charging electrolytes and highlight cathode–electrolyte redox dynamics and structure–property relationships. These insights establish design principles to guide next-generation lithium batteries and broaden the landscape of electrochemical energy storage systems.