Preparation and Electrochemical Properties of Manganese Hexacyanocobaltate
In this study,the manganese hexacyanocobaltate(MnHCC)was synthesized by room temperature coprecipitation method with potassium cobaltocyanide(PH)and manganese chloride(MCT)as raw materials.XRD analysis indicated that the diffraction peaks of MnHCC match the standards in JCPDS Card No.51-1898,with sharp and narrow peaks,suggesting good crystallinity of MnHCC.Fourier-transform infrared(FTIR)spectroscopy revealed a peak at 2156.9cm attributed to the C-N stretching vibration in Co-CN-Mn,and a peak at 449.6cm 1 characteristic of Co-CN in MnHCC,confirming the successful synthesis of MnHCC via the precipitation method.SEM testing revealed that the material primarily consists of dodecahedral equiaxed grains.The particles were uniformly dispersed and no agglomeration was observed.The particle size ranges was 200～700 nm.In electrochemical testing,MnHCC served as the positive electrode,zinc as the negative electrode,and the electrolytes were aqueous solutions of ZnSO4 or Na2SO4.The discharge voltage platform was approximately 1.5V in both 1mol/L ZnSO4+0.1mol/L Na2SO4 and 1mol/L ZnSO4 electrolytes,with discharge specific capacities of 90.44mAh/g and 70.49mAh/g,respectively.Batteries with 0.1mol/L ZnSO4+1mol/L Na2SO4 and 1mol/L Na2SO4 electrolytes had lower discharge specific capacities,less than 20mAh/g.Therefore,Na2SO4 was chosen as the electrolyte.Electrochemical impedance spectroscopy(EIS)and cyclic voltammetry(CV)tests showed two pairs of oxidation-reduction peaks corresponding to the Co2+/Co3+and Mn2+/Mn3+redox couples.The EIS results demonstrated high impedance and weak electronic activity before cycling,which improved after 500 cycles,indicating enhanced electronic activity of the electrode.
manganese hexacyanocobaltateprussian bluenormal temperature coprecipitationwater-based zinc ion battery
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