Grafted MXene/polymer electrolyte for high performance solid zinc batteries with enhanced shelf life at low/high temperatures

The Zn metal anodes of aqueous zinc ion batteries (ZIBs) suffer from dendrites and severe side reactions, such as the hydrogen evolution reaction (HER) and passivation, which seriously restrict the shelf life of ZIBs. Herein, these issues were addressed with a solid polymer electrolyte (SPE) based on the poly(vinylidene fluoride-co-hexafluoropropylene) filled by the poly(methyl acrylate) grafted MXenes (denoted as PVHF/MXene-g-PMA) for the first time. Homogeneously dispersed MXenes were achieved benefiting from the intriguing interaction between the highly grafted PMA and PVHF matrix. The resulting SPE exhibits three orders of magnitude larger ionic conductivity than the PVHF matrix, reaching 2.69 x 10^-4 S cm^-1 at room temperature. Dendrite-free Zn plating/stripping with high reversibility was achieved (over 1000 h cycles at room temperature and 200 h at high temperature). Subsequently, the fabricated solid full cells with eliminated HER and suppressed anode dendrites exhibited excellent cycling performance of 10 000 cycles at 2C at room temperature and could work normally at temperatures ranging from -35 °C to 100 °C. Most importantly, over 90 days of shelf life was attained for the all-solid-state ZIBs after storage at low/high temperatures. Our work represents a substantial progress on the all-solid-state ZIBs with superior stability and reliability, reflected by the effectively suppressed dendrites and side reactions, excellent cycling performance and remarkable shelf life.