# Branched Polyacrylonitrile Enabling Highly Lithium-Ion-Conductive Polymer Plastic Crystal Electrolytes

## TL;DR

This paper introduces a new branched polymer that improves lithium-ion transport in solid-state batteries, making them more efficient and stable.

## Contribution

A novel branched polyacrylonitrile is synthesized using controlled radical polymerization, enhancing electrolyte performance.

## Key findings

- Branched polyacrylonitrile enables faster lithium-ion transport in polymer plastic crystal electrolytes.
- The branched architecture improves ionic conductivity and electrochemical stability compared to linear polymers.

## Abstract

Advancing the development of high-performance solid-state
electrolytes
is critical for realizing next-generation lithium metal batteries.
Among promising candidates, polymer–succinonitrile composites
have emerged as effective polymer plastic crystal electrolytes, demonstrating
enhanced electrochemical performance. However, further improvements
are needed to meet practical application requirements. In this study,
we report a novel strategy for synthesizing electrochemically stable
branched polyacrylonitrile through controlled/living branching radical
polymerization, employing 2-chloroacrylonitrile as an innovative inibramer.
The unique branched architecture of the resulting polymer facilitates
continuous pathways, enabling rapid lithium-ion transport when incorporated
in polymer plastic crystal electrolytes. Electrochemical characterization
reveals substantial improvements in both ionic conductivity and stability
compared to conventional linear counterparts. These findings highlight
the pivotal role of polymer architectural design in optimizing ion
transport within solid electrolytes, offering new opportunities for
developing safer and more efficient energy storage devices.