Imaging dendrite growth in solid-state sodium batteries using fluorescence tomography technology
Shuaishuai Yang, Na Li, Enyue Zhao, Chengzhi Wang, Jingxin He, Xiong Xiao, Debao Fang, Qing Ni, Xile Han, Xiaobin Xue, Lai Chen, Ning Li, Jingbo Li, Tuan Guo, Yuefeng Su, Haibo Jin
Abstract
Dendrite growth in solid-state sodium batteries (SSBs) is one of the most concerned issues that critically affect the battery efficiency and cycling performance. Here, by designing a fluorescent Eu 3+ -doped Na 3 Zr 2 Si 2 PO 12 solid electrolyte (SE) to facilitate three-dimensional (3D) optical imaging on a confocal laser scanning microscopy, a fluorescence tomography (FT) method is developed for observing the sodium dendrite growth during charge/discharge cycles of the SSBs in a 3D view. It is quantitatively revealed that small-size sodium islands appear after several cycles, and with the cycles increasing, large-size dendrites in tens of micrometers gradually form until a critical sodium dendrite volume arrives where a short circuit or severe performance deterioration occurs. Furthermore, by regulating the Eu 3+ doping ratio, a record-high sodium plating/stripping cycling stability for more than 1 year (487.5 days) is achieved at 25°C. This work demonstrates an FT method observing sodium dendrite growth in SSBs and will promote the functional design of high-performance SEs.