PEO/PVDF–HFP/LLZTO Composite Solid Polymer Electrolyte for High-Performance All-Solid-State Lithium Metal Batteries

Abstract

A composite solid polymer electrolyte (CSPE) is the best candidate in all-solid-state lithium metal batteries because of its flexibility, high safety, wide electrochemical stability, relatively high ionic conductivity, and excellent compatibility with the lithium metal. In this work, the garnet-type Li 6.75 La 3 Zr 1.75 Ta 0.25 O 12 (LLZTO) is introduced into a poly(ethylene oxide) (PEO)/poly(vinylidene fluoride−hexafluoropropylene) (PVDF−HFP)-based CSPE (PEO/ PVDF−HFP/LLZTO CSPE). The PEO/PVDF−HFP/LLZTO CSPE possesses a high lithium-ion transference number of 0.47, a high ionic conductivity of 2.65 × 10 −4 S cm −1 , a wide electrochemical window of 5.55 V vs Li + /Li, and effective inhibition of lithium dendrite growth for 1000 h with a current density of 0.10 mA cm −2 . Furthermore, the Li//LiFePO 4 cell assembled with the PEO/PVDF−HFP/LLZTO CSPE delivers superior rate capability and good cycling stability. Therefore, the PEO/PVDF−HFP/LLZTO CSPE is a very promising candidate for high-performance all-solid-state lithium metal batteries.

Garnet-Type Composite Polymer Electrolyte for Room-Temperature All-Solid-State Li–S Battery

“…However, when the filler content exceeded 20%, ionic conductivity decreased due to severe agglomeration of the inorganic fillers in the polymer matrix. At lower LLAZO contents, the addition of LLAZO NFs enhanced the ionic conductivity of CPEs by improving the transport ability of polymer chain segments for ions, achieved through increased amorphous phase and lowered glass transition temperature. − This enhancement is supported by Lewis acid–base theory, where the surface groups of LLAZO NFs interact with ion pairs, promoting more Li + dissociation. Additionally, LLAZO, recognized as an active filler with numerous continuous defects and low activation energy, introduced additional lithium ions and facilitated easy ion hopping, thereby augmenting the concentration of free lithium ions at the interface between the active filler and the polymer. , …”

Novel Strategy for Designing rGO@LLZTO@Li Composite Lithium Powder Anodes with a Dual Conducting Ion-Electron Channel for High-Energy-Density Lithium Metal Batteries

“…In order to prevent the formation and growth of Li dendrites, several efforts have been attempted. These include polymer electrolytes, − inorganic solid electrolytes, − modified separator, functional electrolyte additives, artificial solid electrolyte interphase, − and so on. − However, they still cannot reach the target of practical electrochemical performance. A promising alternative is the lithium powder anode (LPA) instead of traditional plain Li foil anode whose high surface area can reduce the local current density during the process of Li plating/stripping .…”