Garnet-type oxide is one of the most promising solid-state electrolytes (SSEs) for solid-state lithium-metal batteries (SSLMBs). However, the Li dendrite formation in garnet oxides obstructs the further development of the SSLMBs seriously. Here, we report a high-performance garnet oxide by using AlN as a sintering additive and Li as an anode interface layer. AlN with high thermal conductivity can promote the sintering activity of the garnet oxides, resulting in larger particle size and higher relative density. Moreover, Li 3 N with high ionic conductivity formed at grain boundaries and interface can also improve Li-ion transport kinetics. As a result, the garnet oxide electrolytes with AlN show enhanced thermal conductivity, improved ionic conductivity, reduced electronic conductivity, and increased critical current density (CCD), compared with the counterpart using Al 2 O 3 sintering aid. In addition, Li symmetric cells and Li∣LiFePO 4 (Li∣LFP) half cells using the garnet electrolyte with the AlN additive exhibit good electrochemical performances. This work provides a simple and effective strategy for high-performance SSEs.
Zhengpeng Song,Haotong Li,Fei Zheng,Husitu Lin,Jing Liu,Wei Liu,Guohua Sun,Xia Tao
Ceramic Li1.3Al0.3Ti1.7(PO4)3 (LATP) with high ionic conductivity and stability in ambient atmosphere is considered to be potent as a solid-state electrolyte of solid-state lithium metal batteries (SSLMBs), but its huge interfacial impedance with electrodes and the unwanted Ti4+-mediated reduction reaction caused by the lithium (Li) metal anode greatly limit its application in LMBs. Herein, a composite polymer electrolyte (CPET) was integrated by in situ gelation of dual-permeable 1, 3-dioxolane (DOL) in the tandem framework composed of the commercial cellulose membrane TF4030 and a porous three-dimensional (3D) skeleton-structured LATP. The in situ gelled DOL anchored in the tandem framework ensured nice interfacial contact between the as-prepared CPET and electrodes. The introduction of the porous 3D LATP endowed CPET the increased lithium-ion migration number (tLi+) of 0.70, a wide electrochemical stability window (ESW) of 4.86 V, and a high ionic conductivity of 1.16 × 10–4 S cm–1 at room temperature (RT). Meanwhile, the side reaction of the LATP/Li metal was adequately restrained by inserting TF4030 between the porous LATP and Li anode. Profiting from the superb interfacial stability and the enhanced ionic transport capacity of CPET, Li/Li batteries based on the optimal CPET (CPET2) cycled over 2000 h at 20∼30 °C smoothly. Moreover, solid-state LiFePO4 (LFP)/Li with CPET2 exhibited excellent electrochemical performance with a capacity retention ratio of 72.2% after 400 cycles at 0.5C. This work offers an integrated strategy to guide the fabrication of a highly conductive solid electrolyte and a stable interface design for high-performance SSLMBs.
Yi Zou,Wentao Zhao,Shixin Liu,Hui Fang,Lvjin Gao,Yuting Wang,Yinli Su,Li Chen,Zhaolin Liu
Graphical In this study, an innovative AN-based copolymers gel polymer electrolyte is envisaged by introducing a crosslinker-EGDMA and high-strength glass fiber skeleton, which achieves superior electrochemical properties through the synergistic effect between C≡N and C=O. Furthermore, it is facilitated effectively to inhibit the growth of lithium dendrites, which is demonstrated by XPS and SEM. Solid-state lithium-metal batteries (SSLMBs) have attracted great attention due to their outstanding advantages in safety, electrochemical stability and interfacial compatibility. However, the low ionic conductivity and narrow electrochemical window restrict their practical application. Herein, in-situ polymerization electrolytes (IPEs) crosslinked by acrylonitrile (AN) and ethylene glycol dimethacrylate (EGDMA) exhibit the superior ionic conductivity of 1.77×10 −3 S cm −1 at 25 °C, the ultrahigh lithium transference number (tLi+) of 0.784 and the wider electrochemical stable window (ESW) of 5.65 V. The IPEs make the symmetrical Li||Li cells achieve the highly stable lithium stripping/plating cycling for over 3000 h at 0.1 mA cm −2 . Meanwhile, IPE endows the solid-state LiFePO 4 ||Li batteries with an excellent long-cycle performance over 700 cycles at 2.5 C with a capacity retention ratio over 95 %, as well as 1000 cycles at 1 C and superior capacity retention of 85 %. More importantly, the in-situ polymerized electrolytes containing polyacrylonitrile (PAN) open up a new frontier to promote the practical application of solid-state batteries with high safety and high energy density via in-situ solidification technology.