Breaking Mass Transport Limit for Hydrogen Evolution‐Inhibited and Dendrite‐Free Aqueous Zn Batteries

Abstract It is commonly accepted that batteries perform better at low current densities below the mass‐transport limit, which restricts their current rate and capacity. Here, it is demonstrated that the performance of Zn metal electrodes can be dramatically enhanced at current densities and cut‐off capacities exceeding the mass‐transport limit by using pulsed‐current protocols. These protocols achieve cumulative plating/stripping capacities of 11.0 Ah cm −2 and 3.8 Ah cm −2 at record‐high current densities of 80 and 160 mA cm −2 , respectively. The study identifies and understands the promoted (002)‐textured Zn growth and suppressed hydrogen evolution based on the thermodynamics and kinetics of competing reactions. Furthermore, the over‐limiting pulsed‐current protocol enables long‐life Zn batteries with high mass loading (29 mg cathode cm −2 ) and high areal capacity (7.9 mAh cm −2 ), outperforming cells using constant‐current protocols at equivalent energy and time costs. The work provides a comprehensive understanding of the current‐capacity‐performance relationship in Zn plating/stripping and offers an effective strategy for dendrite‐free metal batteries that meet practical requirements for high capacity and high current rates.