Lithium-Rich Anti-perovskite Li₂OHBr-Based Polymer Electrolytes Enabling an Improved Interfacial Stability with a Three-Dimensional-Structured Lithium Metal Anode in All-Solid-State Batteries

Abstract

All-solid-state lithium-metal batteries, with their high energy density and high-level safety, are promising next-generation energy storage devices. Their current performance is however compromised by lithium dendrite formation. Although using 3D-structured metal-based electrode materials as hosts to store lithium metal has the potential to suppress the lithium dendrite growth by providing a high surface area with lithiophilic sites, their rigid and ragged interface with solid-state electrolytes is detrimental to the battery performance. Herein, we show that Li2OHBr-containing poly­(ethylene oxide) (PEO) polymer electrolytes can be used as a flexible solid-state electrolyte to mitigate the interfacial issues of 3D-structured metal-based electrodes and suppress the lithium dendrite formation. The presence of Li2OHBr in a PEO matrix can simultaneously improve the mechanical strength and lithium ion conductivity of the polymer electrolyte. It is confirmed that Li2OHBr does not only induce the PEO transformation of a crystalline phase to an amorphous phase but also serves as an anti-perovskite superionic conductor providing additional lithium ion transport pathways and hence improves the lithium ion conductivity. The good interfacial contact and high lithium ion conductivity provide sufficient lithium deposition sites and uniform lithium ion flux to regulate the lithium deposition without the formation of lithium dendrites. Consequently, the Li2OHBr-containing PEO polymer electrolyte in a lithium-metal battery with a 3D-structured lithium/copper mesh composite anode is able to improve the cycle stability and rate performance. The results of this study provide the experimental proof of the beneficial effects of the Li2OHBr-containing PEO polymer electrolyte on the 3D-structured lithium metal anode.

Recent Advances in All-Solid-State Lithium–Oxygen Batteries: Challenges, Strategies, Future

“…Anti-perovskites (Li 2 OHX, where X = Cl, Br, F) are a specific type of anti-perovskite solid electrolyte that have high ionic conductivities, low-temperature processability, and a high electrochemical stability window [118]. Recent studies have shown that Li-rich anti-perovskite Li 2 OHBrbased PEs can be utilized as a flexible SSE to promote the performance of batteries [119]. Anti-perovskite electrolytes are excellent options for use in SSBs due to their structural flexibility and tunability [120].…”

“…ies [119]. Anti-perovskite electrolytes are excellent options for use in SSBs due to their structural flexibility and tunability [120].…”

Research progress in stable interfacial constructions between composite polymer electrolytes and electrodes

“…Li composites and Li hosted in a 3D structure are different strategies to inhibit the generation of dendrites. [163][164][165] The reasons for using Li alloys and Li compounds as anodes for SSBs are as follows: (1) this type of compound has a smaller nucleation overpotential which makes it easier to induce lithium nucleation and precipitation. (2) It is lithiophilic and induces uniform deposition of lithium.…”

Revisiting the Role of Hydrogen in Lithium‐Rich Antiperovskite Solid Electrolytes: New Insight in Lithium Ion and Hydrogen Dynamics

“…By replacing the flammable liquid electrolyte with nonflammable solid electrolytes (SEs), all‐solid‐state Li metal batteries (ASSLMBs) are considered as safer alternatives for energy storage compared with the commercial Li‐ion batteries. [ 1–13 ] Among the reported families of SEs, Li‐rich antiperovskite (LiRAP) SEs (e.g., Li 3 OCl) possess the advantages of high Li ion conductivity (10 −3 S cm −1 ), low activation energy (<0.3 eV), wide electrochemical window, light weight, low cost, and low toxicity, [ 14–21 ] which show great promises for practical applications. They have a similar crystal structure to the conventional perovskites but with electronically inverted lattice sites.…”

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storage compared with the commercial Li-ion batteries. [1][2][3][4][5][6][7][8][9][10][11][12][13] Among the reported families of SEs, Li-rich antiperovskite (LiRAP) SEs (e.g., Li 3 OCl) possess the advantages of high Li ion conductivity (10 −3 S cm −1 ), low activation energy (<0.3 eV), wide electrochemical window, light weight, low cost, and low toxicity, [14][15][16][17][18][19][20][21] which show great promises for practical applications. They have a similar crystal structure to the conventional perovskites but with electronically inverted lattice sites.

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