Chemically cross-linked Poly(vinyl alcohol) and halloysite nanotubes as composite separator for stable Zn-organic battery

Zn-organic batteries (ZOBs) are promising energy-storage device owing to their merits of high capacity, low cost, and sustainability. However, their electrochemical performance is limited by irreversible organic smallmolecular cathode due to the shuttle effect of discharge intermediates. Here, we report on the use of a chemically cross-linked poly(vinyl alcohol) films with halloysite nanotubes (GA-PVA/HNTs) as a separator for ZOBs. The GA-PVA/HNTs separator with intrinsic electro-negativity of HNTs act as permselective shield for negatively redox organic resultants, thereby preventing the shuttling effect without sacrificing power. In order to illustrate the superior performance of the GA-PVA/HNTs separator, a battery using as-prepared GA-PVA/HNTs separator, benzoquinone (BQ) as the cathode and Zn as the anode displays a high initial capacity (435 mAh g-1 at 0.3C) and superior cycle performance (98% capacity retention after 200 cycles at 3C). Moreover, a flexible Zn||BQ battery based on GA-PVA/HNTs separator is constructed, achieving a highly stable capacity of 431 mAh g-1 under different bending conditions. This work promotes the development of high absorptivity separator for the flexible zinc batteries.