Effects of Molecular Weight on the Electrochemical Properties of Poly(vinylidene difluoride)-Based Polymer Electrolytes.

Polymer-based electrolytes have attracted ever-increasing attention for solid-state batteries due to their excellent flexibility and processability. Among them, poly(vinylidene difluoride) (PVDF)-based electrolytes with high ionic conductivity, wide electrochemical stability window, and good mechanical properties show great potential and have been widely investigated by using different Li salts, solvents, and inorganic fillers. Here, we report the influence of the molecular weight of PVDF itself on the electrochemical properties of the electrolytes by using two kinds of common PVDF polymers, i.

Ion-Dipole Interaction Regulation Enables High-Performance Single-Ion Polymer Conductors for Solid-State Batteries.

Solid polymer electrolytes with large ionic conductivity, high ionic transference number, and good interfacial compatibility with electrodes are highly desired for solid-state batteries. However, unwanted polarizations and side reactions occurring in traditional dual-ion polymer conductors hinder their practical applications. Here, single-ion polymer conductors (SIPCs) with exceptional selectivity for Li-ion conduction (Li-ion transference number up to 0.

Synthesis and Electrochemical Property of FeOOH/Graphene Oxide Composites.

A facile ultrasonication method was used to uniformly mix nanospindle-shaped FeOOH (80-100 nm) and a conductive matrix of graphene oxide (GO) to form FeOOH/GO composites. No carbon peak was observed in the X-ray diffraction pattern, indicating that the graphene oxide did not stack together and that the dispersion of graphene was very high. X-ray photoelectron spectroscopy (XPS) tests showed that the formation of Fe-O-C bonds played a positive role in electron transport, revealing that it has a certain impact on the electrochemical performance of FeOOH/GO.

Self-Suppression of Lithium Dendrite in All-Solid-State Lithium Metal Batteries with Poly(vinylidene difluoride)-Based Solid Electrolytes.

Polymer-based electrolytes have attracted ever-increasing attention for all-solid-state lithium (Li) metal batteries due to their ionic conductivity, flexibility, and easy assembling into batteries, and are expected to overcome safety issues by replacing flammable liquid electrolytes. However, it is still a critical challenge to effectively block Li dendrite growth and improve the long-term cycling stability of all-solid-state batteries with polymer electrolytes. Here, the interface between novel poly(vinylidene difluoride) (PVDF)-based solid electrolytes and the Li anode is explored via systematical experiments in combination with first-principles calculations, and it is found that an in situ formed nanoscale interface layer with a stable and uniform mosaic structure can suppress Li dendrite growth.