TOWARDS SAFER BATTERIES SOLID-STATE ELECTROLYTES AND INTERFACE STABILIZATION MECHANISMS

Abstract

Background: Solid-state batteries are being explored as safer options than traditional lithium-ion batteries due to the increased safety from the solid-state electrolytes which reduce risks associated with thermal runaway, leakage and flammability. But they are limited in practical performance by the instability of the electrode/electrolyte interfaces, the resistance at the interfaces, the formation of dendrites and chemo-mechanical degradation during cycling.

Objective: This work was motivated by the desire to consider the role of solid-state electrolytes and interface stabilization mechanisms for safer and longer lasting battery systems.

Method: The method used is literature based, which involves searching for studies in recent years and selecting those published in 2021-2026 that are peer-reviewed. The review was mainly concerned with oxide, sulfide, polymer, composite and quasi-solid electrolytes, highlighting the following areas: ionic conductivity, electrochemical stability, area-specific resistance, lithium dendrite suppression, artificial interphases, and cathode/electrolyte compatibility.

Result: The results indicated that oxide electrolytes results in thermal/mechanical stability, sulfide electrolytes results in high ionic conductivity, polymer electrolytes results in flexibility and composite systems results in a balance of conductivity and interfacial contact. However, the quality of the interface rather than the type of electrolyte was the major factor for safety and performance. Electron-blocking interlayers, lithiophilic coatings, cathode protective layers, molecular anchoring, entropy-stabilized interfaces and dynamically adaptive interphases decreased interfacial degradation, ensured uniform Li+ flux and inhibited dendrite growth and enhanced cycling stability.

Conclusion: Solid-state electrolytes are a potential pathway to safe, high-energy batteries, but scalable, stable and mechanically adaptable interfaces are needed for commercialization. Good engineering of the interfaces will be key to minimizing short-circuit, durability, and to implement lithium metal solid-state battery applications.