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XJTU researchers reveal new mechanism of anionic redox reactions in sodium-ion batteries

August 05, 2024
  L M S

To meet the growing demand for energy storage, sodium-ion batteries (SIBs) are widely regarded as a cost-effective alternative to lithium-ion batteries due to their abundant raw materials and cost efficiency. Developing layered oxide cathode materials that involve lattice oxygen in redox reactions is an effective strategy to enhance the energy density of SIBs. However, anionic redox reactions often face challenges during the dynamic deintercalation of sodium ions, such as irreversible electrochemical reactions and detrimental structural distortions. Therefore, regulating the reversibility of anionic redox while stabilizing the dynamic phase evolution during the reaction is critical to achieving extra capacity and energy density, which is crucial for developing high-energy-density SIB cathode materials with anionic redox participation.

Addressing the aforementioned issues, Professor Wang Pengfei and Professor Xiao Bing's team from the School of Electrical Engineering at XJTU has designed a sodium-based layered cathode material with lithium orbital hybridization. By introducing a special Na-O-Li configuration, their aim is to stimulate the unhybridized O 2p orbitals to participate in charge compensation. 

Their research reveals a new mechanism of lithium orbital hybridization chemistry in the anionic redox reactions and structural evolution of sodium-ion cathode materials, providing scientific guidance for the development of high-energy-density sodium-ion battery cathode materials.

The research results, titled "Lithium Orbital Hybridization Chemistry to Stimulate Oxygen Redox with Reversible Phase Evolution in Sodium-Layered Oxide Cathodes", have recently been published in the prestigious international journal Journal of the American Chemical Society. PhD student Dong Haojie from XJTU is the lead author of the paper, with Professors Wang and Xiao from XJTU and Professor Wu Xinglong from Northeast Normal University serving as the corresponding authors.