Work

Li + Diffusion in Li n CoNb 2 O 6 (0 < n ≤ 6) Anode with High Capacity Density: Fast Kinetics and Mechanistic Insights

Year: 2025

Type: article

Abstract: The potential of high power/capacity density and Li + solid diffusion mechanisms of niobium‐based binary metal oxide (CoNb 2 O 6 ) anode material are investigated by combining high‐rate Nb 2 O 5 with the redox‐active 3d transition metal Co. CoNb 2 O 6 exhibited exceptional rate capability and cycling stability, which is attributed to anisotropic expansion during cycling and dual diffusion mechanisms at high and low lithium concentrations. The anisotropic expansion of crystals ensures structural stability, whereas the organic combination of a direct‐hopping diffusion mechanism in Li n CoNb 2 O 6 (0 ≤ n ≤ 3) and a knock‐off diffusion mechanism in Li n CoNb 2 O 6 (3 < n ≤ 6) based on the nudged elastic band (NEB) calculations reveals rapid Li + solid diffusion and excellent rate performance during lithiation/delithiation. The electrochemical performance of CoNb 2 O 6 also depends on its morphology, where different structures modulate synergistic Nb and Co interactions, influencing Li + diffusion in the Nb layers. Specifically, the micron‐scale structure formed by secondary particle attachment (CoNb 2 O 6 ‐MP) provides space for anisotropic expansion, fully utilizing the dual ion diffusion mechanism, enhancing diffusion efficiency, and delivering both high‐capacity density and excellent rate performance. This work not only introduces CoNb 2 O 6 with superior electrochemical properties but also provides insights into the solid diffusion mechanisms under various lithium concentrations, offering a foundation for designing electrode materials with enhanced ion diffusion pathways.

Source: Advanced Science

DOI: 10.1002/advs.202416001

Authors: Yimo Xiang, Shaowen Tan, Jingxian Yu, Shengping Wang

Institutions: China University of Geosciences, Guilin University of Technology, Guangxi Key Laboratory of Electrochemical and Magnetochemical Functional Materials, The University of Adelaide

Language: English

Topic: Advancements in Battery Materials

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

SDG: Affordable and clean energy

Open Access status: gold

Estimated APC paid: $6,730