Interphase Building of Organic–Inorganic Hybrid Polymer Solid Electrolyte with Uniform Intermolecular Li⁺ Path for Stable Lithium Metal Batteries

Abstract

Lithium (Li) metal has been generally noticed as the most prospective anode for next‐generation batteries attributed to its outstanding theoretical capacity and low electrochemical potential. Nevertheless, the unstable solid‐electrolyte interphase (SEI) and uncontrollable dendrite growth cause poor reversibility and fetter the practical application of Li metal anodes. Herein, a new organic–inorganic hybrid polymer artificial SEI (POSS‐LiBMAB) layer with uniform lithium‐ion paths at a molecular level is designed to stabilize Li metal anodes. The SEI layer is constructed by the thiol–ene “click chemistry” reaction between inorganic polyhedral oligomeric silsesquioxane containing eight‐mercaptopropyl (POSS‐SH) with lithium bis (allylmalonato) borate (LiBMAB) on Li foil. What is more, the POSS‐LiBMAB film can be cross‐linked and self‐reinforced via intermolecular SC bonds. Benefiting from its flexible polymeric covalent structure and noble inorganic Si8O16‐type cubes, the organic–inorganic hybrid polymer layer is flexible and effectively tolerates the volume change of Li metal anodes during plating/stripping cycles. In addition, this layer shows loose and uniformly distributed electrostatic interaction between Li+ and charge delocalized sp3 boron–oxygen anions, which aids to form a uniform intermolecular Li+ path regulating the homogeneous distribution of Li+ flux on Li anodes. Finally, the designed POSS–LiBMAB layer has high ionic conductivity and lithium‐ion transference number, which can effectively promote Li+ diffusion and guide Li deposition beneath the SEI layer. Therefore, with the protection of the POSS‐LiBMAB layer, the Li metal anode exhibits stable cycling at 5 mA cm−2 for more than 1000 h, and the LFP//Li full cells also present outstanding cycling stability.

Toward Dendrite-Free Metallic Lithium Anodes: From Structural Design to Optimal Electrochemical Diffusion Kinetics

“…(LiBMAB) on Li foil via the thiolene "click chemistry" reactions. 127 In this design, the organic and inorganic materials are closely cross-linked and self-reinforced through the S−C chemical bond formation. Benefiting from the porous polymeric covalent structure and noble inorganic Si 8 O 16 -type cubes, the organic/inorganic hybrid film appears to be selfstanding and flexible enough to accommodate large volume changes after several cycles (Figure 5F).…”

“…(F) The structure and digital photograph of POSS-LiBMAB film. Reproduced with permission from ref . Copyright 2021, Wiley-VCH.…”

“…Another strategy for achieving a strong connection between inorganic and organic components to facilitate rapid lithium ion transport is by manipulating the chemical activity of organic molecules to generate more cross-linked frameworks. Liu and his co-workers designed a SEI layer with inorganic polyhedral oligomeric silsesquioxane containing eight-mercaptopropyl (POSS-SH) and lithium bis (allylmalonato) borate (LiBMAB) on Li foil via the thiolene “click chemistry” reactions . In this design, the organic and inorganic materials are closely cross-linked and self-reinforced through the S–C chemical bond formation.…”

Hybrid Artificial Solid Electrolyte Interphase with Dendrite-Free Lithium Deposition and High Ion Transport Kinetics

“…Comparison with previously reported electrochemical performances of artificial SEI protected Li symmetric cell in the liquid cell. [21][22][23][24][25][26] The cumulative plated-stripped capacity was obtained by multiplying the cycle number and areal capacity. Table S2.…”

Dual-functional 3D carbon fibers decorated with Co nanoparticles and Co-Nx sites for rechargeable aprotic Li–O2 batteries

“…7,8 Several strategies have been explored to deal with the anodic and cathodic problems separately. As for the Li anode, there are various approaches to inhibit the dendrite growth, such as building an artificial layer on the Li surface with strong mechanical strength and high chemical stability, 9,10 exploring electrolyte additives, 11,12 using three-dimensional (3D) substrate, 13,14 and using solid-state electrolyte. 15,16 Recently, functional interlayers [17][18][19] have been developed to improve the Li plating/stripping performance during battery cycling because they have sufficient buffer space and perpetual electrical conduction network to ensure tight Li deposition and lasting electron transfer path.…”