School of Metallurgy and Environment, Central South University, Changsha, Hunan 410083, China.
National Engineering Research Center of Low-carbon Nonferrous Metallurgy, Central South University, Changsha, Hunan 410083, China.
ACS Appl Mater Interfaces. 2023 Jul 5;15(26):31572-31583. doi: 10.1021/acsami.3c06118. Epub 2023 Jun 21.
All-solid-state lithium metal batteries (ASSLMBs), as a candidate for advanced energy storage devices, invite an abundance of interest due to the merits of high specific energy density and eminent safety. Nevertheless, issues of overwhelming lithium dendrite growth and poor interfacial contact still limit the practical application of ASSLMBs. Herein, we designed and fabricated a double-layer composite solid electrolyte (CSE), namely, PVDF-LiTFSI-LiAlTi(PO)/PVDF-LiTFSI-BN (denoted as PLLB), for ASSLMBs. The reduction-tolerant PVDF-LiTFSI-BN (denoted as PLB) layer of the CSE tightly contacts with the Li metal anode to avoid the reduction of LATP by the electrode and participates in the formation of a stable SEI film using LiN. Meanwhile, the oxidation-resistance and ion-conductive PVDF-LiTFSI- LATP (denoted as PLA) layer facing the cathode can reduce the interfacial impedance by facilitating ionic migration. With the synergistic effect of PLA and PLB, the Li/Li symmetric cells with sandwich-type electrolytes (PLB/PLA/PLB) can operate for 1500 h with ultralong cycling stability at 0.1 mA cm. Additionally, the LiFePO/Li cell with PLLB maintains satisfactory capacity retention of 88.2% after 250 cycles. This novel double-layer electrolyte offers an effective approach to achieving fully commercialized ASSLMBs.
全固态锂金属电池 (ASSLMB) 作为先进储能装置的候选者,由于其高比能量密度和卓越的安全性而引起了广泛的关注。然而,锂枝晶生长和界面接触不良等问题仍然限制了 ASSLMB 的实际应用。在此,我们设计并制备了一种双层复合固态电解质 (CSE),即聚偏二氟乙烯-双三氟甲烷磺酰亚胺-锂铝钛(PO)/聚偏二氟乙烯-双三氟甲烷磺酰亚胺-氮化硼 (PLLB),用于 ASSLMB。CSE 的耐还原聚偏二氟乙烯-双三氟甲烷磺酰亚胺-氮化硼 (PLB) 层与锂金属阳极紧密接触,以避免 LATP 被电极还原,并通过 LiN 参与形成稳定的 SEI 膜。同时,与阴极接触的氧化还原和离子导电聚偏二氟乙烯-双三氟甲烷磺酰亚胺-锂磷氧氮 (PLA) 层可以通过促进离子迁移来降低界面阻抗。在 PLA 和 PLB 的协同作用下,采用三明治型电解质 (PLB/PLA/PLB) 的 Li/Li 对称电池可在 0.1 mA cm 的超低电流密度下稳定运行 1500 h,具有超长的循环稳定性。此外,采用 PLLB 的 LiFePO/Li 电池在 250 次循环后仍保持 88.2%的满意容量保持率。这种新型双层电解质为实现全商业化 ASSLMB 提供了一种有效的方法。