Revisiting the ion dynamics in Li <sub> <i>x</i> </sub> CoO <sub>2</sub> and Na <sub> <i>x</i> </sub> CoO <sub>2</sub>
Layered oxides (AMO<sub>2</sub>, where A = Li or Na and M = transition metal) are essential positive electrode materials for lithium- and sodium-ion batteries. A fundamental question in ion transport is whether Li<sup>+</sup> or Na<sup>+</sup> diffuses faster in these materials; however, distinguishing intrinsic diffusion properties from the effects of particle size and electrode composition is challenging. Using <i>operando</i> muon spin spectroscopy and molecular dynamics simulations, we determined the Li<sup>+</sup> and Na<sup>+</sup> self-diffusion coefficients in O3-Li <sub><i>x</i></sub> CoO<sub>2</sub>, O3-Na <sub><i>x</i></sub> CoO<sub>2</sub>, and P2-Na <sub><i>x</i></sub> CoO<sub>2</sub>. Our findings revealed that Na<sup>+</sup> diffusion is higher in the P2-type structure than in the O3-type structure primarily due to weaker electrostatic interactions. In the O3-type structure, Li<sup>+</sup> diffuses faster than Na<sup>+</sup>, whose larger ionic size hinders mobility. These insights clarify the ion transport mechanisms and advance the design of next-generation battery materials.
Authors
- Kei Kubota (ORCID: https://orcid.org/0000-0001-8941-3650)
- Jumpei Nakamura (ORCID: https://orcid.org/0000-0002-8381-5074)
- Izumi Umegaki (ORCID: https://orcid.org/0000-0001-9271-3574)
- Daisuke Igarashi (ORCID: https://orcid.org/0000-0002-4107-3367)
- Martin Må̊nsson (ORCID: https://orcid.org/0000-0002-3086-9642)
- Masanobu Nakayama (ORCID: https://orcid.org/0000-0002-5113-053X)
- Tomooki Hosaka (ORCID: https://orcid.org/0000-0002-5922-8320)
- Jun Sugiyama (ORCID: https://orcid.org/0000-0002-0916-5333)
- Shinichi Komaba (ORCID: https://orcid.org/0000-0002-9757-5905)
- Kazuki Ohishi (ORCID: https://orcid.org/0000-0003-1494-6502)
- Ryoichi Tatara (ORCID: https://orcid.org/0000-0002-8148-5294)
- Rasmus Palm (ORCID: https://orcid.org/0000-0002-1129-9234)
- A. Koda (ORCID: https://orcid.org/0000-0002-4453-4472)
- Eun Jeong Kim (ORCID: https://orcid.org/0000-0002-2941-0682)
- Hiroto Ohta (ORCID: https://orcid.org/0000-0002-0268-9468)
Institutions
- Doshisha University (JP)
- High Energy Accelerator Research Organization (JP)
- Tokyo University of Science (JP)
- Nagoya Institute of Technology (JP)
- National Institute for Materials Science (JP)
- Comprehensive Research Organization for Science and Society (JP)
- Institute of Materials Structure Science (JP)
- KTH Royal Institute of Technology (SE)
Publication Details
- Journal
- Chemical Science
- Published
- 2025-01-01
- DOI
- https://doi.org/10.1039/d5sc03394b
- Citations
- 4
- Primary Topic
- Advancements in Battery Materials
- Type
- article
- Field-Weighted Citation Impact
- 2.92
Funders
- Ministry of Education, Culture, Sports, Science and Technology
- Japan Society for the Promotion of Science
- National Institute for Materials Science
- Core Research for Evolutional Science and Technology
- Precursory Research for Embryonic Science and Technology