Accelerated Diffusion Kinetics in ZnTe/CoTe₂ Heterojunctions for High Rate Potassium Storage

authored by

Chaofeng Zhang, Hao Li, Xiaohui Zeng, Shibo Xi, Rui Wang, Longhai Zhang, Gemeng Liang, Kenneth Davey, Yuping Liu, Lin Zhang, Shilin Zhang, Zaiping Guo

Abstract

Potassium-ion batteries hold practical potential for large-scale energy storage owing to their appealing cell voltage and cost-effective features. The development of anode materials with high rate capability and satisfactory cycle lifespan, however, is one of the key elements for exploiting this electrochemical energy storage system at practical levels. Here, a template-assisted strategy is reported for acquiring a bimetallic telluride heterostructure which is supported on N-doped carbon shell (ZnTe/CoTe₂@NC) that promotes diffusion of K⁺ ions for rapid charge transfer. It is shown that in telluride heterojunctions, electron-rich Te sites and built-in electric fields contributed by electron transfer from ZnTe to CoTe₂ concomitantly provide abundant cation adsorption sites and facilitate interfacial electron transport during potassiation/depotassiation. The relatively fine ZnTe/CoTe₂ nanoparticles imparted by the heterojunction result in high structural stability, together with a highly reversible capacity up to 5000 cycles at 5 A g⁻¹. Moreover, using judiciously combined experiment and theoretical computation, it is demonstrated that the energy barrier for K⁺ diffusion in telluride heterojunctions is significantly lower than that in individual counterparts. This quantitative design for fast and durable charge transfer in telluride heterostructures can be of immediate benefit for the rational design of batteries for low-cost energy storage and conversion.

Organisation(s)

Institute of Solid State Physics

External Organisation(s)

Anhui University
University of Wollongong
A-STAR
University of Adelaide

Type

Article

Journal

Advanced energy materials

Volume

12

No. of pages

9

ISSN

1614-6832

Publication date

03.11.2022

Publication status

Published

Peer reviewed

Yes

ASJC Scopus subject areas

Renewable Energy, Sustainability and the Environment, General Materials Science

Sustainable Development Goals

SDG 7 - Affordable and Clean Energy

Electronic version(s)

https://doi.org/10.1002/aenm.202202577 (Access: Open)