Manganese-Based Spinel Cathodes: A Promising Frontier for Solid-State Lithium-Ion Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• All-solid-state lithium-ion batteries (ASSLIBs) offer enhanced safety and energy density over conventional lithium-ion batteries (LIBs).
• Manganese-based spinel cathodes, such as LiMn2O4 (LMO) and LiNi0.5Mn1.5O4 (LNMO), are cost-effective and structurally stable with 3D Li-ion diffusion channels, showing potential for ASSLIBs.
• Despite their advantages, LMO and LNMO face challenges including structural degradation, poor interfacial contact, high interfacial resistance, and Mn dissolution, limiting their practical application in ASSLIBs.

Purpose of the Study:

• To explore the spinel structure, electrochemical behavior, and degradation mechanisms of LMO and LNMO cathodes.
• To review and introduce mitigating strategies for challenges encountered when pairing LMO/LNMO with various solid-state electrolytes (SSEs).
• To discuss future research directions for advancing Mn-based spinel cathodes for next-generation ASSLIBs.

Main Methods:

• Exploration of spinel structure, electrochemical performance, and degradation pathways of LMO/LNMO.
• Review of recent advancements in solid-state electrolytes (SSEs) including polymer-, oxide-, composite-, sulfide-, halide-, and LiPON-based systems.
• Analysis of compatibility and interfacial issues between Mn-based spinel cathodes and diverse SSEs.

Main Results:

• LMO and LNMO exhibit potential for ASSLIBs due to their low cost and structural stability.
• Significant challenges remain, including structural degradation, interfacial resistance, and electrochemical incompatibility with certain SSEs, particularly for high-voltage LNMO.
• Various SSEs, including polymer, oxide, composite, sulfide, halide, and LiPON, have been investigated for compatibility with LMO/LNMO.

Conclusions:

• Mn-based spinel cathodes (LMO/LNMO) are promising but require strategies to overcome degradation and interfacial challenges for ASSLIBs.
• Addressing the electrochemical incompatibility between high-voltage LNMO and SSEs is crucial for practical application.
• Future research should focus on developing robust Mn-based spinel cathodes and compatible SSEs to realize the full potential of next-generation ASSLIBs.