Source abstract
Abstract
The effect of nanosizing on the sodium storage performance in NaCrO2 is systematically examined. Cation-disordered rock-salt-type and nanosized NaCrO2 is prepared by mechanical milling, and layered O3-type and nanosized NaCrO2 is prepared by heat treatment of the rock-salt phase. The observation by high-resolution transmission electron microscopy reveals that secondary particles consist of highly crystalline and nanosized NaCrO2 primary particles with enriched grain boundaries. Such morphological features influence the voltage profiles in sodium cells, leading to an S-shaped profile with a single-phase reaction even for layered NaCrO2, in which a biphasic reaction dominates because of a large repulsive interaction between Na ions. Moreover, the O3–P3 phase transition is suppressed for the heat-treated sample with the presence of enriched grain boundaries. The suppression of the phase transition is proposed to be due to the cancellation of CrO2 layers gliding for the incoherently aligned grain boundaries. Thus, good capacity retention as electrode materials is realized compared with as-prepared bulk O3 NaCrO2. Nanotechnology potentially changes materials design strategies for sodium insertion materials, leading to the development of innovative rechargeable sodium batteries in the future.
Source: openalex_inverted_index · Quality: baseline
Affiliations
Department of Applied Chemistry, Tokyo Denki University, 5 Senju Asahi-Cho, Adachi, Tokyo 120-8551, Japan
Institute for Frontier Materials, Deakin University, 75 Pigdons Road, Waurn Ponds, Geelong, Victoria 3216, Australia
Department of Chemical and Biomolecular Engineering, The University of Melbourne, Parkville, Victoria 3010, Australia
Elements Strategy Initiative for Catalysts and Batteries, Kyoto University, f1-30 Goryo-Ohara, Kyoto 615-8245, Japan
Funding
Ministry of Education, Culture, Sports, Science and Technology · Advanced Low Carbon Technology Research and Development Program