An Electrochromic Nickel Phosphate Film for Large-Area Smart Window with Ultra-Large Optical Modulation

Exploring materials with high electrochemical activity is of keen interest for electrochemistry-controlled optical and energy storage devices.However,it remains a great challenge for transition metal oxides to meet this feature due to their low electron conductivity and insufficient reaction sites.Here,we propose a type of transition metal phosphate(NiHPO_(4)·3H_(2)O,NHP)by a facile and scalable electrodeposition method,which can achieve the capability of efficient ion accommodation and injection/extraction for electrochromic energy storage applications.Specifically,the NHP film with an ultra-high transmittance(approach to 100%)achieves a large optical modulation(90.8%at 500 nm),high coloration efficiency(75.4 cm^(2)C^(-1)at 500 nm),and a high specific capacity of 47.8 mAh g^(-1)at 0.4 A g^(-1).Furthermore,the transformation mechanism of NHP upon electrochemical reaction is systematically elucidated using in situ and ex situ techniques.Ultimately,a large-area electrochromic smart window with 100 cm^(2)is constructed based on the NHP electrode,displaying superior electrochromic energy storage performance in regulating natural light and storing electrical charges.Our findings may open up new strategies for developing advanced electrochromic energy storage materials and smart windows.

Spatially controlled lithium deposition on Li_(x)Cu_(y)P_(z) arrays enabling highly stable lithium metal batteries

Lithium(Li)metal is a potential anode for high-energy-density batteries because of its low potential and ultrahigh capacity.Nevertheless,the Li dendrites formation,the ununiform Li deposition,and the growth of Li dendrites hamper its application,especially under high deposition capacity/high rate.Here,a spatially controlled Li deposition mode with array-oriented morphology is achieved based on the novel mixed ion/electron-conducting Li_(x)Cu_(y)P_(z) arrays constructed on Cu foil,which can be facile fabricated via an in-situ transformation of metal phosphide.Theoretic calculations indicate the excellent lithiophilicity and low Li diffusion barrier of the arrays,especially for the Li_(2)CuP phase,which are conducive to ho-mogenizing the Li nucleation/deposition of Li.Moreover,such mixed conducting arrays promote fast Li+diffusion via the continuous Li+pathways as well as modulate the Li+flux/electric field.Furthermore,the arrays with enlarged specific surface area and open spaces reduce the local current density and alle-viate the volume fluctuation of Li.Consequently,a dendrite-free Li anode is obtained under a high rate(20 mA cm^(–2))or a high deposition capacity(10 mAh cm^(–2)).In addition,even if the negative/positive ratio reduces to only 1.1,the full cells still perform outstanding stability for over 200 cycles.This work empha-sizes the importance of the design of the framework in terms of the intrinsic properties and structure and reveals a pathway for developing Li metal batteries.

Mixed-dimensional hierarchical configuration of 2D Ni_(2)P nanosheets anchored on 1D silk-derived carbon fiber for extraordinary electromagnetic wave absorption

Considering a series of electromagnetic pollution problems brought by the development of electronic communication technology,more attention has been paid to the research of electromagnetic wave(EMW)absorbing materials with unique composition and structure.Herein,under the inspiration of mixeddimensional hierarchical structure,2D Ni_(2)P nanosheets anchored on 1D silk-derived carbon fiber is successfully fabricated as a gratifying resistor-dielectric type absorber.By a controllable pyrolyzation strategy and disproportionated reaction,high-density 2D Ni_(2)P nanosheets were grown vertically and cross-linked on the surface of 1D silk-derived carbon fiber.The sample exhibited superior EMW absorption performance with maximum reflection loss value of–56.9 d B at the thickness of 2.32 mm and the effective absorption bandwidth can reach to 7.2 GHz at the thickness of 1.93 mm.In addition,the pure Ni_(2)P shows remarkable dielectric characteristic and EMW absorption ability as well.The integration of dualconductive loss,enhanced polarization relaxation loss and the multiple scattering in the composites was proved to contribute to the good EMW absorption performance.Therefore,this work confirms the great potentials of Ni_(2)P as a high-efficient EMW absorbing materials and light a new way in construction of multidimensional absorber.

Molecular and nanostructure designed superhydrophilic material with unprecedented antioil-fouling property for diverse oil/water separation

The design and development of new advanced superwetting porous membranes with antioil-fouling performance are still rare and highly desirable because of their potential widespread applications.A metallic phosphate nanoflower-covered mesh membrane with superhydrophilic and unprecedented antioil-fouling properties is prepared by an exceptionally simple and effective in-situ solution corrosion method.As demonstrated,the outstanding antioil-fouling property of the resulting mesh membrane is connected with the special phosphate group and the three-dimensional(3 D) nanoflower structure.Owing to the antioil-fouling property,upon to water,the oil-fouled mesh membrane can keep the surface free of various kinds of oils,including viscous crude oil to light n-hexane.Thanks to its unprecedented self-cleaning property,the superhydrophilic mesh membrane can effectively separate different oil/water mixtures without prior wetted by water,exhibiting great potential for practical spilled oil remediation.