Lin, J;
Zhao, S;
Tranter, TG;
Zhang, Z;
Peng, F;
Brett, D;
Jervis, R;
(2023)
Modelling and experimental investigation of Nb2O5 as a high-rate battery anode material.
Electrochimica Acta
, 443
, Article 141983. 10.1016/j.electacta.2023.141983.
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Abstract
Modelling and understanding the battery electrochemical performance at high rates is a great challenge. Known for its fast rate and good cyclability, niobium pentoxide (Nb2O5) is a promising anode material for lithium-ion batteries and is specifically modelled and investigated in this work. Commercially sourced Nb2O5 was characterised using scanning electron microscopy, X-ray diffraction, and micro-computed tomography. The Nb2O5 material was found to contain large rod- and ball-like polycrystalline particles of tens of microns in size and have mixed T-Nb2O5 and H-Nb2O5 phases. The electrochemical performance of the material after ball milling was tested via cyclic voltammetry and constant-current cycling at different C-rates up to 50C (10,000 mA g−1). The material achieved a similar charge capacity (143 mAh g−1) to T-Nb2O5 at 0.5C and this capacity could be retained by more than 55% when C-rate was increased to 10C. The experimental results were used to support the development of the Doyle-Fuller-Newman electrochemical model for Nb2O5. By model parameterization, the reference exchange-current density and solid-state diffusivity of the present Nb2O5 were estimated to be 9.6 × 10−4 A m−2 and 6.2 × 10−14 m2 s−1, respectively. The model achieved accurate prediction of the battery performance up to currents of 5C with the obtained constant properties. However, the properties of Nb2O5 were found to be rate-dependent at higher C-rates when good agreements between the model and experiment were maintained. The decrease of the two properties at 10−50C revealed that there was a change of dominant charge storage mechanism from diffusion-controlled lithium insertion to capacitive effects, which was experimentally observed in the cyclic voltammetry.
| Type: | Article |
|---|---|
| Title: | Modelling and experimental investigation of Nb2O5 as a high-rate battery anode material |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1016/j.electacta.2023.141983 |
| Publisher version: | https://doi.org/10.1016/j.electacta.2023.141983 |
| Language: | English |
| Additional information: | © 2023 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/). |
| Keywords: | Niobium pentoxide, Lithium-ion battery, Characterization, Model, Charge storage |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Engineering Science > Dept of Chemical Engineering |
| URI: | https://discovery.ucl.ac.uk/id/eprint/10165071 |
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