Flexible hybrid solid electrolyte incorporating ligament-shaped Li6.25Al0.25La3Zr2O12 filler for all-solid-state lithium-metal batteries

• Published in: Electrochimica acta Vol. 366; p. 137348
• Main Authors: Beshahwured, Shimelis Lemma, Wu, Yi-Shiuan, Wu, She-huang, Chien, Wen-Chen, Jose, Rajan, Lue, Shingjiang Jessie, Yang, Chun-Chen
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 10.01.2021; Elsevier BV
• Subjects: Al-doped LLZO; All-solid-state batteries; Aluminum; Cathodes; Diffusion coefficient; Electrolytes; Electrolytic cells; Fillers; Flux density; Heat transmission; Hybrid solid electrolyte; Interconnected ligament–like filler; Ion currents; Ligaments; LiNi0.8Co0.1Mn0.1O2; Lithium; Lithium batteries; Polyacrylonitrile; Polymer blends; Solid electrolytes; Solid state; Succinonitrile; Vinylidene; Vinylidene fluoride; Al-doped LLZO; LiNi0.8Co0.1Mn0.1O2; Interconnected ligament–like filler; All-solid-state batteries; Hybrid solid electrolyte
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2020.137348

•HSE membrane based on 5, 12 and 20 wt% Al-doped LLZO@PVDF-HFP/PAN/LiClO4/SN was successfully prepared by using a solution-casting method and 12 wt% is the optimum amount of filler for this work.•The HSE exhibited a high ionic conductivity of 1.12 × 10−4 S cm−1 at 25 °C, wider electrochemical stability window up to 4.2 V (Li/Li+), and a high transference number of 0.42±0.025.•A full cell based on c-NCM811/HSE/Li shows highest discharge specific capacity of 160.92 and 144.70 mAh g−1 at 0.1 C and 0.2C rates at room temperature, respectively.•The in-situ heat flow profile of c-NCM811/HSE/Li, b-NCM811/HSE/Li and c-NCM811/SPE/Li cells was investigated, and lower heat profile was displayed for c-NCM811/HSE/Li cell.•The cell also displayed excellent electrochemical performance in terms of rate recovery when tested at various C-rates. In this study we used a solution-casting method to fabricate a hybrid solid electrolyte (HSE) membrane based on a poly(vinylidene fluoride–co–hexafluoropropylene)/polyacrylonitrile (PVDF-HFP/PAN) polymer blend loaded with an interconnected ligament–shaped Li6.25Al0.25La3Zr2O12 (Al-doped LLZO) filler and applied it in all-solid-state lithium-metal batteries (ASSLMBs). The as-prepared HSE containing the optimized quantity of Al-doped LLZO@PVDF-HFP/PAN/LiClO4/succinonitrile filler displayed high ionic conductivity (1.12 × 10–4 S m–1 at 25 °C), a wide electrochemical stability window [up to 4.2 V (Li/Li+)], and a high transference number (0.42). A full cell based on the composite cathode NCM811 (LNi0.8Co0.1Mn0.1O2, c-NCM811)/HSE/Li had a highest discharge specific capacity of 160.92 mA h g–1 at 0.1 C and a capacity retention of 92.52% after 100 cycles; at 0.2 C, these values were 144.70 mA h g–1 and 85.72% (after 100 cycles), respectively. The Li+ diffusion coefficient of the c-NCM811/HSE/Li cell was one order of magnitude higher than that of the corresponding cell having a bare cathode (b-NCM811/HSE/Li) as well as c-NCM811/SPE+10%SN/Li. We used a multiple-mode calorimetry device to investigate the in situ heat flow profiles of c-NCM811/HSE/Li, c-NCM811/SPE/Li, and b-NCM811/HSE/Li cells; the c-NCM811/HSE/Li cell exhibited the lowest heat profile. Thus, ASSLMBs featuring the NCM811 composite cathode and this as-prepared HSE have great potential for use in applications requiring batteries of high energy density. Scheme for formation HSE SEM image of as-prepared 3D interconnected ligament-like shape garnet-type ionic conductor by a simple double-template method [Display omitted]