Muhammad Zaheer,Hongli Xu,Bingbing Wang,Lianwei Li,Yonghong Deng
High ionic conductivity is a prerequisite for the application of solid-state polymer electrolyte towards the safe and high energy density electrochemical devices. Here we report the preparation and properties of an in-situ polymerized comb-like copolymer-based SPE (PLA/PEG-SPE) with high ionic conductivity from methyl acrylate functionalized poly(D,L-Lactide) (PLAMA) and poly(ethylene glycol) methyl ether methacrylate (PEGMA). A remarkably high ionic conductivity value of 6.9 × 10−5 S cm−1 at ambient temperature and a maximum ionic conductivity of 4.3 × 10−4 S cm−1 at 60°C were detected, with an activation energy of 0.2 eV and a Li+ transference number (tLi+) of 0.36. The PLA/PEG-SPE exhibits a wide electrochemical stability window up to 4.6 vs. Li/Li+ and very good lithium metal electrode compatibility. Solid-state LiFePO4/SPE/Li cells with integrated cathode and lithium metal deliver superior cycling stability with high discharge capacities (149 mAh g−1 as the initial specific capacity) and high capacity retention (exceeded 82% of its initial specific capacity) at 0.2 C at 60°C. The solid-state cells are also capable of being cycled at room temperature at 0.2 C. This work highlights a facile, in-situ fabrication strategy involving a vinyl-functionalized PLA precursor that yields a high-performance ion-conducting membrane attractive for lithium metal battery applications.
Polyethylene oxide (PEO) based solid-state electrolytes are known for the low manufacturing cost and excellent processability, but their practical application is paved with thorns including the inferior ionic conductivity, low Li + transfer number and insufficient Li dendrite blocking ability. Herein, we propose organic montmorillonite (OMMT) with expanded layer spacing (1.97 nm) as versatile fillers to construct PEO-OMMT electrolyte, in which OMMT not only increases Li + transfer number (0.56) and ionic conductivity (7.15 × 10 −4 S cm −1 ), providing fast ionic transport channels, but also endows PEO with high mechanical strength, resulting remarkable Li dendrite blocking ability (>2100 h). Additionally, the high dielectric constant and Lewis-rich polar sites of OMMT facilitate the dissociation of lithium salts and the rapid formation of LiF and Li 3 N-rich solid electrolyte interface layers. Impressively, the LiFePO 4 | PEO-OMMT | Li cell shows a high initial capacity (154.4 mAh g −1 at 0.5C) with ultralong cycling lifespan (>1200 cycles). Similarly, the LiNi 0.83 Mn 0.05 Co 0.12 O 2 | PEO-OMMT | Li cell retains a high discharge capacity of 151.5 mAh g −1 after 100 cycles at 0.2C. This work highlights the indelible contributions of OMMT functionalized fillers in improving the interfacial stability of PEO based solid-state electrolytes, paving a feasible avenue for the practical application of solid-state lithium metal batteries.
危险品化学品经营许可证（带存储）