A Metal-Organic Compound as Cathode Material with Superhigh Capacity Achieved by Reversible Cationic and Anionic Redox Chemistry for High-Energy Sodium-Ion Batteries

Chun Fang; Ying Huang; Lixia Yuan; Yaojun Liu; Weilun Chen; Yangyang Huang; Kongyao Chen; Jiantao Han; Qingju Liu; Yunhui Huang

doi:10.1002/anie.201701213

A Metal-Organic Compound as Cathode Material with Superhigh Capacity Achieved by Reversible Cationic and Anionic Redox Chemistry for High-Energy Sodium-Ion Batteries

Angew Chem Int Ed Engl. 2017 Jun 6;56(24):6793-6797. doi: 10.1002/anie.201701213. Epub 2017 May 4.

Authors

Chun Fang¹, Ying Huang², Lixia Yuan¹, Yaojun Liu¹, Weilun Chen¹, Yangyang Huang¹, Kongyao Chen¹, Jiantao Han¹, Qingju Liu², Yunhui Huang^{1

3}

Affiliations

¹ State Key Laboratory of Material Processing and Die & Mould Technology, School of Materials Science and Engineering, Huazhong University of Science and Technology, Wuhan, Hubei, 430074, China.
² School of Materials Science and Engineering, Yunnan University, Kunming, Yunnan, 650091, China.
³ Dongguan McNair New Power Co., Ltd, Guangdong, 523800, China.

PMID: 28471036
DOI: 10.1002/anie.201701213

Abstract

Although sodium-ion batteries (SIBs) are considered as alternatives to lithium-ion batteries (LIBs), the electrochemical performances, in particular the energy density, are much lower than LIBs. A metal-organic compound, cuprous 7,7,8,8-tetracyanoquinodimethane (CuTCNQ), is presented as a new kind of cathode material for SIBs. It consists of both cationic (Cu^II ↔Cu^I ) and anionic (TCNQ⁰ ↔TCNQ^- ↔ TCNQ^2- ) reversible redox reactions, delivering a discharge capacity as high as 255 mAh g^-1 at a current density of 20 mA g^-1 . The synergistic effect of both redox-active metal cations and organic anions brings an electrochemical transfer of multiple electrons. The transformation of cupric ions to cuprous ions occurs at near 3.80 V vs. Na⁺ /Na, while the full reduction of TCNQ⁰ to TCNQ^- happens at 3.00-3.30 V. The remarkably high voltage is attributed to the strong inductive effect of the four cyano groups.

Keywords: UV/Vis spectroscopy; cathode materials; electron transfer; metal-organic compounds; redox chemistry.

Publication types

Research Support, Non-U.S. Gov't