A trinity strategy enabled by iodine-loaded nitrogen-boron-doped carbon protective layer for dendrite-free zinc-ion batteries

Multifunctional interfacial layers and porous Zn surface as well as the introduction of electrolyte additives were achieved via a N, B doped carbon bubble-loaded iodine-assisted method, thus allowing the INBC@Zn electrode to exhibit superior cycling stability. [Display omitted] •A trinity composite coating is constructed by N, B doped carbon-loading iodine method.•ZnO interfacial layer, ZnI2 additives and 3D porous structure are in-situ achieved.•ZnO interfacial layer and 3D porous structure modulate the uniform zinc deposition.•The INBC@Zn anode has excellent cycle stability and low nucleation overpotential. Although aqueous zinc ion batteries (AZIBs) have the merits of environmental friendliness, high safety and theoretical capacity, the slow kinetics associated with zinc deposition and unavoidable interfacial corrosion have seriously affected the commercialization of aqueous zinc ion batteries. In this work, an ingenious “trinity” design is proposed by applying a porous hydrophilic carbon-loaded iodine coating to the zinc metal surface (INBC@Zn), which simultaneously acts as an artificial protective layer, electrolyte additive and anode curvature regulator, so as to reduce the nucleation overpotential of Zn and promote the preferential deposition of (002) planes to some extent. With this synergistic effect, INBC@Zn exhibits high reversibility and strong side reaction inhibition. As a result, INBC@Zn shows high symmetric cycling stability up to 4500 h at 1 mA cm−2. An ultra-long cycle stability of 1500 cycles with high Coulombic efficiency (99.8 %) is achieved in the asymmetric cell. In addition, the INBC@Zn//NVO full cells exhibit impressive capacity retention (96 % after 1000 cycles at 3 A/g). Importantly, the designed pouch cell demonstrates stable performance and shows certain prospects for application. This work provides a facile and instructive approach toward the development of high-performance AZIBs.