Division of Energy and Environment, Engineering Laboratory for the Next Generation Power and Energy Storage Batteries, Graduate School at Shenzhen , Tsinghua University , Shenzhen 518055 , China.
School of Materials Science and Engineering , Tsinghua University , Beijing 100084 , China.
ACS Appl Mater Interfaces. 2019 Mar 13;11(10):9911-9918. doi: 10.1021/acsami.8b20413. Epub 2019 Feb 27.
Solid electrolytes are considered as strong alternatives for conventional liquid electrolytes to overcome the safety issues of next-generation high-energy-density lithium metal batteries (LMBs). Although LiAlGe(PO) (LAGP) has satisfied ionic conductivity at room temperature (∼10 S cm), high stability in air, and can be easily sintered, it still suffers from instability of the lithium metal. Moreover, the large interfacial resistance between solid electrolytes and solid electrodes and the stress generated by the volumetric change of lithium metal anodes during cycling would deteriorate the performance of LMBs. Here, we report an effective solution to overcome the abovementioned problems by introducing a three-dimensional gel polymer electrolyte at the interface between LAGP pellets and lithium metal anodes, achieving stable cycling of LiFePO//Li cells at room temperature for 300 cycles. Besides, the degeneration mechanisms of the interfaces of LAGP pellets under different conditions are compared, and peculiar properties different from their counterparts were found.
固体电解质被认为是传统液体电解质的有力替代品，可以克服下一代高能量密度锂金属电池 (LMB) 的安全问题。虽然 LiAlGe(PO) (LAGP) 在室温下具有满足离子电导率 (∼10 S cm)、在空气中的高稳定性以及易于烧结的特点，但它仍然存在锂金属不稳定的问题。此外，固体电解质和固体电极之间的大界面电阻以及锂金属阳极在循环过程中体积变化产生的应力会降低 LMB 的性能。在这里，我们通过在 LAGP 颗粒和锂金属阳极之间的界面引入三维凝胶聚合物电解质，提出了一种有效的解决方案来克服上述问题，从而实现了室温下 LiFePO//Li 电池在 300 次循环中的稳定循环。此外，还比较了 LAGP 颗粒在不同条件下的界面退化机制，并发现了与其对应物不同的特殊性质。
