Stable 2,5-Dihydroxy-1,4-benzoquinone Based Organic Cathode Enabled by Coordination Polymer Formation and Binder Optimization

Abstract

Organic electrode materials are gaining increased attention in energy storage applications, but often encounter challenges such as low capacity and poor cycling stability. This paper explores the utilization of a 1-D coordination polymer, copper(II)-2,5-dihydroxy-1,4-benzoquinone (Cu-DHBQ), as a cathode material for Li-ion batteries for the first time. Cu-DHBQ is air-stable, devoid of coordinated water molecules, and possesses a high theoretical capacity of 266 mAh g−1. With an optimal sodium alginate (SA) binder content of 25 wt%, the Cu-DHBQ cathode demonstrates a notable initial capacity of 214 mAh g−1 and outstanding cycling stability, retaining 210 mAh g−1 (98% capacity retention) after 200 cycles at a current rate of 100 mA g−1. A comprehensive investigation into the capacity fading mechanisms, the bonding capability of the SA binder, and the interactions between Cu-DHBQ and SA is conducted using scanning electron microscope (SEM), peel tests, and Fourier transform infrared spectroscopy (FTIR), respectively. Additionally, the electrochemical reaction mechanisms of Cu-DHBQ are examined using ex situ X-ray photoelectron spectroscopy (XPS) and FTIR. These findings offer valuable insights into understanding the electrochemical properties of coordination polymers and metal-organic frameworks based on DHBQ, shedding light on their potential as materials for battery electrodes.