摘要
Chloride solid electrolytes(SEs)have attracted widespread attention due to their high room-temperature ionic conductivity and excellent cathode compatibility.However,the conventionally selected central metal elements(e.g.,In,Y and Ta)are usually rare and heavy,inevitably causing the high cost and high density of the obtained chloride SEs.Here,by choosing abundant and light Mg and Al as central metal elements,we develop a cheap and low density Li_(1.2)Mg_(0.95)Al_(0.3)Cl_(4)SE for high active material ratio in all solid state cathode.Partial replacement of Mg^(2+)by Al^(3+)in the framework yields vacancies and lowers the non-lithium metal ions occupancy at Mg/Li co-occupied 16d site,effectively relieving the blocking effects by Mg^(2+)in the pristine spinel Li_(2-2x)Mg_(1+x)Cl_(4).Thus,a significantly improved room-temperature conductivity of 3.08×10^(-4)S·cm^(-1)is achieved,two orders of magnitude higher than that of Li_(1.2)Mg_(1.4)Cl_(4).More attractively,its low density of only 1.98 g·cm-3 enables low SE mass ratio in cathodes(only 16 wt.%)with still effective electrolyte/cathode contact and lithium-ion conduction inside.When charged to potential of 4.30 V,the asfabricated Li_(1.2)Mg_(0.95)Al_(0.3)Cl_(4)-based solid lithium battery with uncoated NCM523 cathode can be cycled for over 100 cycles with a capacity retention of 86.68%at room temperature.
基金
the National Natural Science Foundation of China(Nos.22325505,52073271,and 22305236)
the USTC Research Funds of the Double First-Class Initiative(No.YD2060002034)
the Collaborative Innovation Program of Hefei Science Center,CAS(No.2022HSC-CIP018)
the China Postdoctoral Science Foundation(Nos.2023M733375 and 2023T160619).
作者简介
Hao-Yuan Tan,contributed equally to this work;Mei-Yu Zhou,contributed equally to this work;Zhongyuan Huang,contributed equally to this work;Address correspondence to:Yi-Chen Yin,artist@mail.ustc.edu.cn;Address correspondence to:Yinguo Xiao,y.xiao@pku.edu.cn;Address correspondence to:Hong-Bin Yao,yhb@ustc.edu.cn。
