Preparation of fully flexible lithium metal batteries with free-standing β-Na0.33V2O5 cathodes and LAGP hybrid solid electrolytes

Abstract

Safe and flexible batteries are expected to be the enabler for advancing the technology of wearable electronics to an unforeseen level in near future. However, to date the energy density of such devices is rather limited due to the rather large proportion of dead weight and volume to provide good flexibility. To overcome this hurdle, a disruptive change in the battery manufacturing process is needed. Herein, we not only introduce a simple phase inversion method for the preparation of free-standing and flexible β-Na0.33V2O5 cathodes without metal current collector, but also demonstrate the possibility to integrate those into fully flexible lithium metal batteries. Additionally, employing a LAGP-based hybrid solid electrolyte enables excellent high temperature stability and thus, enhanced safety characteristics of the device. Such integrated flexible batteries exhibit fast and stable lithium-ion storage capabilities, with a large specific capacity of 228mAh g−1 at 0.1C and excellent cycling stability translating into an outstanding specific energy of 407.8 Wh kg−1 on electrode level.