Decoding High-voltage LiCoO₂: From Degradation to Stabilization Toward Durable Li-ion Batteries.

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Lithium-ion batteries (LIBs) with Lithium Cobalt Oxide (LCO) cathodes are vital for portable electronics.
• Increasing energy density is critical for advanced smart devices, often requiring higher operating voltages.
• Elevating cut-off charging voltage above 4.6 V enhances capacity but causes severe LCO degradation.

Purpose of the Study:

• To highlight the need for high-voltage cathodes in modern LIBs.
• To investigate the failure mechanisms of LCO cathodes at high voltages (up to 4.6 V).
• To systematically evaluate strategies for stabilizing high-voltage LCO and improving electrochemical performance.

Main Methods:

• Review of literature on LCO failure mechanisms at elevated voltages.
• Analysis of various stabilization techniques including foreign-ion doping, surface modifications, and structural design.
• Discussion of electrolyte additives and innovative full-cell designs for LCO-based systems.

Main Results:

• High-voltage operation of LCO leads to significant material degradation and battery failure.
• Stabilization strategies like doping, surface coating, and electrolyte additives can mitigate degradation.
• Optimized battery designs and modifications show promise for enhancing LCO performance.

Conclusions:

• Addressing LCO degradation is crucial for realizing high-energy, durable LIBs.
• Further research into rational design and modification strategies is needed for advanced high-voltage cathode materials.
• This review provides guiding principles for developing next-generation high-voltage LIBs.