Ordaz Mariana Vargas, Pavlin Nejc, Gastaldi Matteo, Gerbaldi Claudio, Dominko Robert
National Institute of Chemistry, Hajdrihova 19, Ljubljana SI-1000, Slovenia.
Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, Ljubljana SI-1001, Slovenia.
ACS Appl Mater Interfaces. 2024 Dec 11;16(49):68237-68246. doi: 10.1021/acsami.4c13335. Epub 2024 Nov 25.
The thermodynamically unstable interface between metallic lithium and electrolyte poses a major problem for the massive commercialization of Li-metal batteries. In this study, we propose the use of a multicomponent protective coating based on cellulose modified with dimethylthexylsilyl group (TDMSC), single-ion conducting polymer P(LiMTFSI), and LiNO (TDMSC-P(LiMTFSI)-LiNO, namely PTL). The coating shows its positive effect by increasing the Coulombic efficiency in Li || Cu cells from 95.9 and 98.6% for bare Li, to >99.3% for Li coated (Li@PTL), with 1 M LiFSI in FEC:DEC and 1 M LiFSI in DME electrolyte, respectively. Symmetrical Li || Li PTL-coated cells exhibit a much more prolonged and stable cycling with a slower increase in overpotential compared to bare Li cells. Li@PTL anodes enable improved cycling of Li@PTL/LFP cells compared to noncoated cells in liquid electrolytes. In this respect, inhibition of high surface area lithium growth is confirmed through postcycling scanning electron microscopy. Remarkably, dendrite-free galvanostatic cycling is demonstrated in laboratory-scale solid-state battery cells assembled with LFP composite cathode (catholyte configuration with PEO + LiTFSI as ionically conducting binder) and a cross-linked PEO-based solid polymer electrolyte. The PTL protective coating enables improved stability of Li metal batteries in combination with smooth transport of Li at the electrode-electrolyte interface and homogeneous lithium coating, highlighting its promising prospects in enhancing the performance and safety of lithium metal batteries by properly tuning the synergy between the coating components.
金属锂与电解质之间热力学不稳定的界面给锂金属电池的大规模商业化带来了一个主要问题。在本研究中，我们提出使用一种基于用二甲基叔丁基硅烷基（TDMSC）改性的纤维素、单离子导电聚合物P（LiMTFSI）和LiNO（TDMSC-P（LiMTFSI）-LiNO，即PTL）的多组分保护涂层。该涂层通过将Li||Cu电池中的库仑效率从裸锂的95.9%和98.6%分别提高到涂覆锂（Li@PTL）的>99.3%，显示出其积极效果，电解质分别为1 M LiFSI的FEC:DEC和1 M LiFSI的DME。与裸锂电池相比，对称的Li||Li PTL涂覆电池表现出更长时间和更稳定的循环，过电位增加更慢。与液体电解质中的未涂覆电池相比，Li@PTL阳极使Li@PTL/LFP电池的循环性能得到改善。在这方面，通过循环后扫描电子显微镜证实了高比表面积锂生长的抑制。值得注意的是，在组装有LFP复合阴极（以PEO + LiTFSI作为离子导电粘合剂的阴极电解液配置）和交联PEO基固体聚合物电解质的实验室规模固态电池中，展示了无枝晶恒电流循环。PTL保护涂层通过在电极-电解质界面实现锂的平稳传输和均匀锂涂层，提高了锂金属电池的稳定性，突出了其通过适当调节涂层组分之间的协同作用在提高锂金属电池性能和安全性方面的广阔前景。
