Challenges and Strategies towards Practically Feasible Solid-State Lithium Metal Batteries

Area of Science:

• Materials Science
• Electrochemistry
• Energy Storage

Background:

• Inorganic solid electrolytes (SEs) with high ionic conductivity (>10 mS cm⁻¹) enable solid-state batteries (SSBs).
• SSBs offer enhanced safety by replacing flammable liquid electrolytes and enabling lithium metal anodes for high-energy density.

Purpose of the Study:

• To review the fundamental challenges hindering the practical application of lithium metal anodes in solid-state lithium metal batteries (SSLMBs).
• To discuss current strategies and future research directions for overcoming these challenges and enabling commercialization.

Main Methods:

• Review of current literature and understanding of interfacial phenomena in SSLMBs.
• Analysis of five key problem areas: interfacial stability, morphological evolution, lithium diffusion, material imperfections, and electronic conductivity of SEs.

Main Results:

• Poor cycle stability and low energy efficiency in SSLMBs are linked to interfacial issues with lithium metal anodes.
• Key challenges include chemical/electrochemical instability, morphological changes, limited lithium diffusivity, defects/pores in SEs, and electronic conductivity of SEs.

Conclusions:

• Addressing interfacial stability, morphology, diffusion, defects, and electronic conductivity is crucial for improving SSLMB performance.
• Further research is needed to achieve commercial-level high-energy SSLMBs with reliable cycle stability and efficiency.