Despite the impressive merits of low-cost and high-safety electrochemical energy storage for aqueous zinc ion batteries, researchers have long struggled against the unresolved issues of dendrite growth and the side reactions of zinc metal anodes. Herein, a new strategy of zinc-electrolyte interface charge engineering induced by amino acid additives is demonstrated for highly reversible zinc plating/stripping. Through electrostatic preferential absorption of positively charged arginine molecules on the surface of the zinc metal anode, a self-adaptive zinc-electrolyte interface is established for the inhibition of water adsorption/hydrogen evolution and the guidance of uniform zinc deposition. Consequently, an ultra-long stable cycling up to 2200 h at a high current density of 5 mA cm −2 is achieved under an areal capacity of 4 mAh cm −2 . Even cycled at an ultra-high current density of 10 mA cm −2 , 900 h-long stable cycling is still demonstrated, demonstrating the reliable self-adaptive feature of the zinc-electrolyte interface. This work provides a new perspective of interface charge engineering in realizing highly reversible bulk zinc anode that can prompt its practical application in aqueous rechargeable zinc batteries.

Pseudomorphic conversion of metal–organic frameworks (MOFs) enables the fabrication of nanomaterials with well-defined porosities and morphologies for enhanced performances. However, the commonly reported calcination strategy usually requires high temperature to pyrolyze MOF particles and often results in uncontrolled growth of nanomaterials. Herein, we report the controlled alkaline hydrolysis of MOFs to produce layered double hydroxide (LDH) while maintaining the porosity and morphology of MOF particles. The preformed trinuclear M3(μ3-OH) (M = Ni2+ and Co2+) clusters in MOFs were demonstrated to be critical for the pseudomorphic transformation process. An isotopic tracing experiment revealed that the 18O-labeled M3(μ3-18OH) participated in the structural assembly of LDH, which avoided the leaching of metal cations and the subsequent uncontrolled growth of hydroxides. The resulting LDHs maintain the spherical morphology of MOF templates and possess a hierarchical porous structure with high surface area (BET surface area up to 201 m2·g–1), which is suitable for supercapacitor applications. As supercapacitor electrodes, the optimized LDH with the Ni:Co molar ratio of 7:3 shows a high specific capacitance (1652 F·g–1 at 1 A·g–1) and decent cycling performance, retaining almost 100% after 2000 cycles. Furthermore, the hydrolysis method allows the recycling of organic ligands and large-scale synthesis of LDH materials.

Lithium ion batteries have attained great success in commercialization owing to their high energy density. However, the relatively delaying discharge/ charge severely hinders their high power applications due to intrinsically diffusion-controlled lithium storage of the electrode. This study demonstrates an ever-increasing surface redox capacitive lithium storage originating from an unique microstructure evolution during cycling in a novel RGO-MnO-RGO sandwich nanostructure. Such surface pseudocapacitance is dynamically in equilibrium with diffusion-controlled lithium storage, thereby achieving an unprecedented rate capability (331.9 mAh g −1 at 40 A g −1 , 379 mAh g −1 after 4000 cycles at 15 A g −1 ) with outstanding cycle stability. The dynamic combination of surface and diffusion lithium storage of electrodes might open up possibilities for designing high-power lithium ion batteries. and high-rate lithium storage capability by tuning the surface pseudocapacitance.Herein, we successfully demonstrate ultrahigh-rate lithium storage in a novel RGO (reduced graphene oxide)-MnO-RGO sandwich nanostructure, in which dynamic equilibrium between surface pseudocapacitance and diffusion-controlled lithium storage is achieved after a novel cycle-induced microstructure evolution ( Figure 1 ). The top and bottom RGO layers provide fast pathway for charge transfer, constrain the aggregation of active materials, and suppress the stress across the whole electrode during lithiation/delithiation. More interestingly, the pulverized manganese oxide nanocrystals generated over cycling are confi ned and trapped on these RGO layers, forming hierarchical RGO-supported manganese oxide nanoclusters. Meanwhile, further oxidation of MnO to Mn 3 O 4 along with cycling, which contributes signifi cantly to the pseudocapacitance, is clearly demonstrated. All the cycle-induced features result in the steadily increased lithium pseudocapacitance with high-rate capability in the RGO-MnO-RGO sandwich nanostructure.

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