A highly conductive and stable hybrid solid electrolyte for high voltage lithium metal batteries †
Understanding Li+ migration behavior in hybrid solid-state electrolytes (HSEs) is essential for realizing the conductivity of HSE and high energy density Li metal batteries. Here, a highly conductive HSE with a continuous lithium-ion (Li+) transport pathway consisting of an anionic-type single Li+ conductor polymer (lithium taurine-grafted poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)-Lix, x represents the amount of lithium taurine)) and Li1.4Al0.4Ti1.6(PO4)3 (LATP) particles are prepared for solid-state lithium metal batteries. The prepared ionomer P(VDF-HFP)-Lix can enhance the transmission efficiency of Li+ in the polymer substrate, forming a “Li+ transport bridge” between inorganic particles to provide rapid and continuous Li+ transmission channels in HSE, and eliminating interface charge accumulation caused by an excessive impedance difference of the polymer/ceramic. The P(VDF-HFP)-Li10-50LATP HSE possesses high ionic conductivity (7.88 × 10−4 S cm−1 at 25 °C), Li+ transference number (tLi+ = 0.61) and electrochemical stability (>5.16 V vs. Li+/Li). Furthermore, the Li‖HSE‖Li symmetrical battery achieves a stability over more than 1000 h at 0.1 mA cm−2, while the HSE-based LiNi0.6Mn0.2Co0.2O2 (NCM622)‖Li and LiNi0.5Mn1.5O4 (LNMO)‖Li batteries show high specific capacity (160 mA h g−1 and 126.8 mA h g−1 at 0.5C) and good cycling stability (capacity retention of 93% and 80% after 200 cycles, respectively). This work provides a an effective to achieve high ionic conductivity and stability for HSEs, simultaneously.
- This article is part of the themed collection: Journal of Materials Chemistry A HOT Papers