Title

Sulfonic-Group-Grafted Ti3C2TxMXene: A Silver Bullet to Settle the Instability of Polyaniline toward High-Performance Zn-Ion Batteries

Publication Name

ACS Nano

Abstract

Polyaniline (PANI) is a promising cathode material for Zn-ion batteries (ZIBs) due to its intrinsic conductivity and redox activity; however, the achievements of PANI in high-performance ZIBs are largely hindered by its instability during the repeated charge/discharge. Taking advantage of the high conductivity, flexibility, and grafting ability together, a surface-engineered Ti3C2Tx MXene is designed as a silver bullet to fight against the deprotonation and swelling/shrinking issues occurring in the redox process of PANI, which are the origins of its instability. Specifically, the sulfonic-group-grafted Ti3C2Tx(S-Ti3C2Tx) continuously provides protons to improve the protonation degree of PANI and maintains the polymer backbone at a locally low pH, which effectively inhibits deprotonation and brings high redox activity along with good reversibility. Meanwhile, the conductive and flexible natures of S-Ti3C2Tx assist the fast redox reaction of PANI and concurrently buffer its corresponding swelling/shrinking. Therefore, the S-Ti3C2Tx-enhanced PANI cathode simultaneously achieves a high discharge capacity of 262 mAh g-1 at 0.5 A g-1, a superior rate capability of 160 mAh g-1 at 15 A g-1, and a good cyclability over 5000 cycles with 100% coulombic efficiency. This work enlightens the development of versatile MXene via surface engineering for advanced batteries.

Open Access Status

This publication is not available as open access

Volume

15

Issue

5

First Page

9065

Last Page

9075

Funding Number

JCYJ20170818142354137

Funding Sponsor

Science and Technology Foundation of Shenzhen City

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Link to publisher version (DOI)

http://dx.doi.org/10.1021/acsnano.1c02215