Polymer Electrolyte Membrane with High Ionic Conductivity and Enhanced Interfacial Stability for Lithium Metal Battery

Abstract

Solid polymer electrolyte is one of the best choices to improve the safety of lithium metal batteries (LMBs). However, its widespread application is hindered because of the low ionic conductivity at room temperature and large interfacial resistance. Here, a cross-linked polymer is synthesized with an unsaturated polyester and used as a polymer electrolyte membrane (PEM). The PEM has a high ionic conductivity (1.99 × 10–3 S cm–1 at 30 °C) and a low glass transition temperature (−54.2 °C), contributing to decreasing interfacial resistance, promoting more uniform Li deposition, and suppressing Li dendrite penetration. The PEM also has a wide electrochemical stable window (∼4.6 V) and superior thermal stability (>150 °C), showing high potential in LMBs. The LiFePO4–Li coin cells and pouch pack batteries with PEM present very stable cycle performance and high safety, indicating that the PEM can be a promising candidate for future solid-state LMBs.

Excellent Performances of Composite Polymer Electrolytes with Porous Vinyl-Functionalized SiO2 Nanoparticles for Lithium Metal Batteries

“…PEO-based CPEs have attracted a large amount of research since they were first applied in solid electrolytes by Armand et al in 1978 [28]. PEO has excellent flexibility, an outstanding ability to dissolve lithium salts, and high ion conductivity at elevated temperatures [29,30]. However, pure PEO electrolyte with inferior mechanical stability is insufficient to restrain the formation of lithium dendrites and the intrinsic high crystallinity of PEO, which results in a poor ionic conductivity originally depending on the amorphous region [31,32].…”

Self‐Healing and Flexible Ionic Gel Polymer Electrolyte Based on Reversible Bond for High‐Performance Lithium Metal Batteries

“…In contrast, the lower T g of IGPE contributes to a tight contact with electrodes and reduces the interfacial resistance between the electrodes and IGPE. [36] The melting enthalpy (ΔH m ) values also change due to the incorporation of LiTFSI and BMImTFSI into the polymer. ΔH m can be calculated by DSC and the crystallinity (X C ) can be estimated with the value of ΔH m according to the following formula…”

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

“…Among the next-generation rechargeable batteries proposed to overcome the limitations of lithium-ion batteries, all-solid-state lithium-metal batteries have drawn the most attention due to their high energy density made possible by pairing a cathode with a lithium metal anode and their use of solid-state electrolytes with good thermal stability and safety from solution leakage. − The development of all-solid-state lithium-metal batteries is however met with several technical challenges. The formation of lithium dendrites leads to irreversible capacity loss and short-circuiting in batteries when the lithium dendrites penetrate through the solid-state electrolyte. , The poor contacts between the electrode and solid-state electrolyte do not only hinder the lithium ion diffusion but also induce the growth of lithium dendrites. , …”

“…The formation of lithium dendrites leads to irreversible capacity loss and short-circuiting in batteries when the lithium dendrites penetrate through the solid-state electrolyte. 7,8 The poor contacts between the electrode and solid-state electrolyte do not only hinder the lithium ion diffusion but also induce the growth of lithium dendrites. 9,10 The majority of the mitigation methods for the lithium dendrite formation developed to date are focused on electrolyte engineering, protective layer introduction, and 3D-structured electrode design.…”