Dissolution Mechanism for Dendrite-Free Aqueous Zinc-Ions Batteries

The commercialization of aqueous Zn-ion batteries (AZIBs) for power-grid energy storage systems is hindered by the safety concerns arising from the Zn dendrite growth. The primary approach in addressing this issue is to induce planar depositions. However, modulating the Zn dissolution process which directly reshapes surface morphology and reserves growth sites has long been overlooked. Herein, by utilizing ester compounds as an illustration, it is revealed that engineering the dissolution energy barrier is a pivotal factor in promoting homogeneous Zn dissolution. Ester adsorbents effectively redistribute charge densities at the electrode-electrolyte interface due to the presence of zincophilic ester functional group and conductive pi-conjugation structure. This effect eventually facilitates Zn dissolution across the surface, transforming the potholed and defective dissolution morphology into a smooth and consistent form. Thus, enhanced cycling stability can be achieved in both half-cells and full-cells, offering an extensive lifespan of thousands of hours for the dissolution and deposition cycles. This work provides a principle for the selection of Zn dissolution improvers to suppress Zn metal dendrite growth by regulating Zn dissolution behavior. The previously disregarded problem of pit formation, which arises from uncontrolled Zn dissolution, has been successfully resolved by manipulating the dissolution energies. Conjugated adsorbents effectively modulate the charge distribution at the electrode-electrolyte interface, engineering dissolution energies and facilitating uniform morphological evolution. image