Affiliation:
1. State Key Lab of Organic-Inorganic Composites Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical Technology Beijing 100029 People's Republic of China
2. Institute of High Energy Physics Chinese Academy of Sciences Beijing 100049 People's Republic of China
3. School of Mechanical and Manufacturing Engineering University of New South Wales Sydney, New South Wales 2052 Australia
Abstract
AbstractTransition metal oxides (TMOs) are key in electrochemical energy storage, offering cost‐effectiveness and a broad potential window. However, their full potential is limited by poor understanding of their slow reaction kinetics and stability issues. This study diverges from conventional complex nano‐structuring, concentrating instead on spin‐related charge transfer and orbital interactions to enhance the reaction dynamics and stability of TMOs during energy storage processes. We successfully reconfigured the orbital degeneracy and spin‐dependent electronic occupancy by disrupting the symmetry of magnetic cobalt (Co) sites through straightforward strain stimuli. The key to this approach lies in the unfilled Co 3d shell, which serves as a spin‐dependent regulator for carrier transfer and orbital interactions within the reaction. We observed that the opening of these ′spin gates′ occurs during a transition from a symmetric low‐spin state to an asymmetric high‐spin state, resulting in enhanced reaction kinetics and maintained structural stability. Specifically, the spin‐rearranged Al−Co3O4 exhibited a specific capacitance of 1371 F g−1, which is 38 % higher than that of unaltered Co3O4. These results not only shed light on the spin effects in magnetic TMOs but also establish a new paradigm for designing electrochemical energy storage materials with improved efficiency.
Funder
National Natural Science Foundation of China