Chen Mingzhe, Hua Weibo, Xiao Jin, Zhang Jiliang, Lau Vincent Wing-Hei, Park Mihui, Lee Gi-Hyeok, Lee Suwon, Wang Wanlin, Peng Jian, Fang Liang, Zhou Limin, Chang Chung-Kai, Yamauchi Yusuke, Chou Shulei, Kang Yong-Mook
Department of Materials Science and Engineering, Korea University, Seoul 02841, Republic of Korea.
Institute for Applied Materials-Energy Storage Systems (IAM-ESS), Karlsruhe Institute of Technology (KIT), 76344 Eggenstein-Leopoldshafen, Germany.
J Am Chem Soc. 2021 Nov 3;143(43):18091-18102. doi: 10.1021/jacs.1c06727. Epub 2021 Oct 19.
The increasing demand to efficiently store and utilize the electricity from renewable energy resources in a sustainable way has boosted the request for sodium-ion battery technology due to the high abundance of sodium sources worldwide. Na superionic conductor (NASICON) structured cathodes with a robust polyanionic framework have been intriguing because of their open 3D structure and superior thermal stability. The ever-increasing demand for higher energy densities with NASICON-structured cathodes motivates us to activate multielectron reactions, thus utilizing the third sodium ion toward higher voltage and larger capacity, both of which have been the bottlenecks for commercializing sodium-ion batteries. A doping strategy with Cr inspired by first-principles calculations enables the activation of multielectron redox reactions of the redox couples V/V, V/V, and V/V, resulting in remarkably improved energy density even in comparison to the layer structured oxides and Prussian blue analogues. This work also comprehensively clarifies the role of the Cr dopant during sodium storage and the valence electron transition process of both V and Cr. Our findings highlight the importance of a broadly applicable doping strategy for achieving multielectron reactions of NASICON-type cathodes with higher energy densities in sodium-ion batteries.
以可持续方式高效存储和利用可再生能源产生的电力的需求不断增加，由于全球钠资源丰富，这推动了对钠离子电池技术的需求。具有坚固聚阴离子框架的钠超离子导体（NASICON）结构的阴极因其开放的三维结构和优异的热稳定性而备受关注。对具有NASICON结构阴极的更高能量密度的需求不断增加，促使我们激活多电子反应，从而将第三个钠离子用于更高的电压和更大的容量，这两者一直是钠离子电池商业化的瓶颈。受第一性原理计算启发的用Cr进行掺杂的策略能够激活氧化还原对V/V、V/V和V/V的多电子氧化还原反应，即使与层状结构氧化物和普鲁士蓝类似物相比，也能显著提高能量密度。这项工作还全面阐明了Cr掺杂剂在钠存储过程中的作用以及V和Cr的价电子跃迁过程。我们的研究结果突出了一种广泛适用的掺杂策略对于在钠离子电池中实现具有更高能量密度的NASICON型阴极的多电子反应的重要性。
