Modulating the zinc ion flux and electric field intensity by multifunctional metal-organic complex interface layer for highly stable Zn anode

The uncontrollable growth of Zn dendrites accompanied by side reactions severely impedes the industrialized process of zinc ion electrochemical energy storage devices.Herein,we propose a practical metalorganic complex interface layer to manipulate the zinc ion flux and electric field intensity,enabling highly homogeneous zinc electrodeposition.The zinc-terephthalic acid complex(ZnPTA)with lower adsorption energy for zinc ion(-1.3 eV)builds a zincophilic interface favoring the ordered nucleation and growth of Zn.Moreover,the ZnPTA layer can serve as physical barrier to protect the newly deposited Zn from corrosion in the aqueous electrolyte.The modified Zn anode with the ZnPTA layer(ZnPTA@Zn)demonstrates excellent cycling stability more than 3000 h at 1 mA/cm^(2).Besides,the zinc-ion battery and zinc-ion hybrid capacitor using the ZnPTA@Zn electrode deliver outstanding cycle performance(up to 5500 cycles with high residual capacity ratio of 77.9%).This work provides a promising metal-organic complex interface design on enhancing the performance of Zn metal anode.

Realizing a dendrite-free metallic-potassium anode using reactive prewetting chemistry

Potassium metal batteries(PMBs)have become a paramount alternative energy storage technology to lithium-ion batteries,due to their low cost and potential energy density.However,uncontrolled dendrite growth interferes with the stability of the interfacial anode,leading to significant capacity degradation and safety hazards.Herein,a facile reactive prewetting strategy is proposed to discourage dendrite growth by constructing a functional KF/Znrich hybrid interface layer on K metal.The KF/Zn@K anode design functions like an interconnected paddy field,stabilizing the anode interface through the preferential redistribution of Kþflux/electrons,continuous transport paths,and enhanced transport dynamics.As anticipated,symmetrical batteries exhibit an extended cycling lifetime of over 2000 h,with reduced voltage hysteresis at 0.5 mA cm^(-2) and 0.5 mAh cm^(-2).Furthermore,when the KF/Zn@K anode is applied to full batteries coupled with PTCDA,a boosted reversible capacity of 61.6 mAh g1 at 5 C is present over 3000 cycles.This interfacial control creates rational possibilities for constructing highefficiency,stable K metal anodes.

Negatively charged insulated boron nitride nanofibers directing subsurface zinc deposition for dendrite-free zinc anodes

The practical application of aqueous zinc-ion batteries(ZIBs)is limited by the growth of dendrite during cycling.How to rationally design and construct an efficient artificial interface layer by selecting suitable building units to control the dendrite growth is still a challenge.Herein,a porous boron nitride nanofibers(BNNFs)artificial interface layer was constructed,and its working mechanisms were revealed by both experiments(electrochemical characterization and in-situ optical microscope)and theoretical calculations(density functional theory(DFT)and finite element simulation).The insulated BNNFs layer leads to position-selected electroplating between BNNFs layer and Zn foil.The unique negatively charged surface and porosity of BNNFs contribute to the self-concentrating and pumping features of Zn ions,thus suppressing the concentration polarization on the Zn surface.Additionally,densely arranged porous BNNFs have a shunt effect on Zn ions diffusion,resulting in uniform distributions of Zn ions and electric field.The introduced BNNFs layer not only makes Zn deposition uniform but also restrains the dendrite growth,therefore the Zn+BNNFs symmetric cells perform ultralong stable cycling for 1,600 h at 1 mA·cm–2 and more than 500 h at 10 mA·cm–2.Moreover,Zn+BNNFs||CNT/MnO2 battery presents a high initial capacity of 293.6 mAh·g–1 and an excellent retention rate of 97.6%at 1 A·g–1 after 400 cycles,while Zn||CNT/MnO2 battery only maintains 37.1%discharge capacity.This artificial interface layer with negatively charged BNNFs exhibits excellent dendrite-inhibit and may have enormous prospects in other metal batteries.