Strategic Research Grant Report: Fiber-shaped lithium-ion batteries with metallic electrodes

TL;DR

This paper reports the development of a fiber-shaped lithium-ion battery using metallic electrodes and a solid electrolyte, demonstrating its electrochemical performance and mechanical flexibility.

Contribution

It introduces a novel fiber LIB design with co-twisted metallic electrodes and a solid electrolyte, showcasing its electrochemical stability and flexibility.

Findings

Open-circuit voltage of ~3.4 V

Specific capacity of ~87 mAhg-1 at 0.5 C

Coulombic efficiency over 82%

Abstract

We have demonstrated a fiber lithium ion battery (LIB) fabricated by co-twisting a LiFePO4 composite-coated copper wire (cathode) together with an aluminum wire (anode). An all-solid LiPF6 composite layer functioning both as the electrolyte and battery separator is deposited onto the two electrode wires before twisting. To characterize the electrochemical properties of the battery, charge-discharge tests with different C-rates are performed. The fiber LIB has an open-circuit voltage of ~3.4 V, and the typical specific capacity is found to be ~87 mAhg-1 at 0.5 C charge-discharge rate. Besides, the proposed battery has a Coulombic efficiency of more than 82% throughout all the charge-discharge tests. We also find that bending of the fiber battery has insignificant influence on the battery electrochemical properties.