A specific free-volume network as synergistic zinc–ion–conductor interface towards stable zinc anode

Abstract

• Benefit from the physical barriers and abundant free volume and plentiful Zn 2+ transport channels of PIMs coating, the stable and dendrite-free Zn anodes are achieved. • The PIM-1 endows the Zn anode with an extremely low nucleation overpotential of 8 mV, and enables a PIM-1@Zn//Cu asymmetric battery to achieve a high average CE of 99.7% for 500 cycles. • The transmission mechanism of Zn 2+ through the O-O path in PIM-1 is revealed by DFT simulations. • The capacity of PIM-1@Zn/NH 4 V 4 O 10 full battery can still reach 170 mAh g −1 after 9500 cycles at 10 A g −1 . The rechargeable aqueous zinc (Zn) ion battery is considered to be the most promising battery due to its inherent safety, low cost and high capacity. However, the Zn anode suffers from the low Coulombic efficiency (CE), irreversible dendritic growth and side reactions. Herein, we separate aqueous electrolyte from Zn anode by coating polymers of intrinsic microporosity (PIMs) layer, which possess unique rigid framework and abundant free volume and provide plentiful storage sites and ordered transport channels for Zn 2+ . The specific protective structure of PIM-1 endows the Zn anode with an extremely low nucleation overpotential of 8 mV, and enables a PIM-1@Zn//Cu asymmetric battery to achieve a high average CE of 99.7% for 500 cycles. The PIM-1@Zn symmetric battery achieves stability for over 2500 h at a current density of 0.5 mA cm −2 . The capacity of PIM-1@Zn/NH 4 V 4 O 10 full battery can still reach 170 mAh g −1 after 9500 cycles at 10 A g −1 . Moreover, the transmission mechanism of Zn 2+ through O-O path in PIM-1 is elucidated by density functional theory (DFT) calculations. This work opens a new avenue for the application of uniform porous polymers in the field of high-performance aqueous batteries.