Jiaxing Lv,Ying Jiang,Guozhong Lu,Xiaobing Lou,Bingwen Hu
In traditional operations of all-solid-state lithium metal batteries (ASSLMBs), a small thin lithium metal circular disk is employed as a lithium metal anode (LMA). However, ASSLMBs with a circular-disk LMA often fail in <150 cycles with low capacity retention. In this work, we developed a new ring-shaped LMA to improve cyclability. Full cells consisting of a ring-shaped LMA, a LiCoO2 cathode, and a Li6PS5Cl electrolyte maintain good capacity retention of 83.65% at 0.3C after 300 cycles. Moreover, in situ L-band electron paramagnetic resonance imaging (EPRI) showed that fewer Li dendrites are formed on a ring-shaped LMA. This work highlights the importance of the design of the shape of the LMA to mitigate the growth of lithium dendrites and shows that L-band EPRI is a useful technique for ASSLMBs.
All-solid-state Li batteries (ASSLBs) with solid-state electrolytes (SSEs) are exciting candidates for next-generation energy storage and receive considerable attention owing to their reliability. Halide SSEs are promising candidates due to their excellent stability against 4 V-class layered cathodes. Compared with Li 3 InCl 6 or Li 3 ScCl 6 , the low ionic conductivity of Li 2 ZrCl 6 (LZC) is a challenge despite its low raw-material cost. Herein, we report a family of Li-Richened chloride, Li 2+2 x Zr 1– x M x Cl 6 , which can be used in high-performance ASSLBs owing to its high ionic conductivity (up to 0.62 mS cm −1 ). The theoretical (ab initio molecular dynamics simulations) and experimental results prove that the strategy of aliovalent substitution with divalent metals to obtain Li-Richened LZC is effective in improving Li + conductivity in SSEs. By combining Li 2.1 Zr 0.95 Mg 0.05 Cl 6 (Mg5-LZC) with a Li–In anode and a LiCoO 2 cathode, a room-temperature ASSLBs with excellent long-term cycling stability (88% capacity retention at 0.3C for 100 cycles) and high-rate capability (121 mA h g −1 at 1C) is reported. This exploratory work sheds light on improving the Li + conductivity of low-cost LZC-family SSEs for constructing high performance ASSLBs.