Asymmetric Polymer Electrolyte Constructed by Metal–Organic Framework for Solid‐State, Dendrite‐Free Lithium Metal Battery

Abstract

Solid-state polymer electrolytes (SPEs) with flexibility, easy processability, and low cost have been regarded as promising alternatives for conventional liquid electrolytes in next-generation high-safety lithium metal batteries. However, SPEs generally suffer poor strength to block Li dendrite growth during the charge/discharge process, which severely limits their wide practical applications. Here, a rational design of 3D cross-linked network asymmetric SPE modified with a metal-organic framework (MOF) layer on one side is proposed and prepared through an in-situ polymerization process. In such unique asymmetric SPEs, the nanoscale MOF layer acts as a shield that effectively suppresses the growth of Li dendrites and regulates the uniform Li + transport, and the polymer electrolyte can be scattered in the whole cell to endow the smooth transmission of Li +. As a result, the asymmetric SPE exhibits high ionic conductivity, wide electrochemical window, high thermal stability and safety, which endows the Li/Li symmetrical cell with outstanding cyclic stability (operate well over 800 h at a current density of 0.1 mA cm −2 for the capacity of 0.1 mAh cm −2).

Li+ Dynamics of Liquid Electrolytes Nanoconfined in Metal–Organic Frameworks

“… 12 Similar results were found in the case of other honeycomb-like structured MOFs with 1D channels along the c -axis, such as the cucurbit[6]uril-based derivatives, which exhibit conductivity of about 0.1 mS cm –1 and high cationic transference number ( t + > 0.7) after incorporation of LiPF 6 into the pores. 14 , 15 …”

Core–Shell MOF‐in‐MOF Nanopore Bifunctional Host of Electrolyte for High‐Performance Solid‐State Lithium Batteries

“…The failure of IL cell after 98 cycles can be attributed to an internal short circuit due to dendrite growth. In addition, the capacity of CSIL cell is higher than other works related to pure MOF electrolytes, [47,53,62] that can be ascribed to the high ionic conductivity, electrochemical stability, interfacial stability, and increased Li + transference number. Also from Figure 4c it can be signaled that the capacity of the battery increases slightly before stabilizing due to an enhanced interface (contact) between CSIL solid electrolyte and electrodes and also attributed to the uniform distribution of Li + on the Li metal electrode surface (Figure S17, Supporting Information).…”

Solid‐State Lithium Metal Batteries with Extended Cycling Enabled by Dynamic Adaptive Solid‐State Interfaces

“…[15,16] Efforts to enhance the solid contact interface have been focused on adding a trace of liquid electrolytes at the interface, constructing a thin artificial alloy interface with high wettability, or designing ceramic-polymer composite electrolytes that could possess both the advantages of ceramic and polymer electrolytes. [17][18][19][20][21][22][23][24][25][26][27][28] For instance, adding extra Li-Al, Li-Si, Li-Au, Li-ZnO, and Li-C/Ag alloy interface layers could improve the wettability of the SSE surface and facilitated rapid Li +transportation at the interface. [17][18][19][20][21][22] These delicate interfaces were more compatible with Li-metal to boost Li-nucleation.…”