Formulation principles and synergistic effects of high-voltage electrolytes

Area of Science:

• Materials Science
• Electrochemistry
• Battery Technology

Background:

• Commercial lithium-ion batteries (LIBs) face limitations in energy density due to cathode potential and capacity.
• Current carbonate-based electrolytes, like LiPF6, degrade under high-voltage conditions, causing oxidative decomposition and unstable interphases.
• Understanding the complex mechanisms of high-voltage electrolytes (HVEs) is essential for next-generation battery development.

Purpose of the Study:

• To provide a comprehensive review of high-voltage electrolytes (HVEs) for LIBs.
• To investigate the chemical environment of high-voltage cathodes and failure modes of commercial electrolytes.
• To explore screening criteria and formulation principles for novel HVEs.

Main Methods:

• Review of physical properties, solvation structures, and interface chemistry of HVEs.
• Analysis of oxidation resistance, decomposition mechanisms, and interphase species based on energy levels.
• Proposal of a cross-scale evolution framework from solvation structure to interphase characteristics.

Main Results:

• Commercial electrolytes exhibit limitations due to oxidative decomposition and unstable interphases.
• Screening criteria for single-component electrolytes and interphase species were explored.
• A framework for understanding formulation principles and synergistic effects in HVEs was proposed.

Conclusions:

• Developing stable HVEs requires understanding solvation structures and interface chemistry.
• A systematic approach integrating computational and experimental methods is key to discovering new electrolyte candidates.
• Further research into entropy-driven effects and multi-component electrolytes will enhance HVE performance.