| With the development of science and technology,energy issues have become the main source of many conflicts in the world,and as an important representative of energy storage technology,battery has become a kind of goods everywhere in people’s life.Lithium-ion battery has been widely used as a common battery material due to its high efficiency.However,the amount of lithium on earth limits its extensive use,so the development of new high-efficiency battery materials has been put on the agenda.Zinc-ion batteries have been listed by researchers as one of the potential alternatives to lithium batteries because of their abundant reserves,relatively cheap cost and environmental friendliness.However,various problems of the negative electrode of zinc ion battery seriously hinder the progress of research,so the method of making coating layer on the metal zinc surface of the negative electrode of battery is proposed to solve the defects of the negative electrode.In this paper,a novel method of making a coating layer to protect the negative electrode of battery by electrophoresis is proposed.In the process of making,the use of adhesive is avoided,the characteristics of the material are preserved to the maximum extent,and the overall efficiency of the battery is improved.The main contents include the following two aspects:（1）Sodium polyacrylate is deposited on the surface of zinc foil by electric field force by electrophoretic method,and different coating layers are obtained by adjusting different electrophoretic voltages（1 V,5 V,10 V）.The coating material with the best electrochemical performance was obtained at 5 V electrophoretic voltage by comparing the apparent and electrochemical properties of the three coatings with blank zinc foils.The coating can effectively prevent the growth of dendrites on the negative electrode surface of the battery and the occurrence of side reactions,so as to reduce the hysteresis voltage of symmetric and asymmetric batteries and improve the battery life and coulomb efficiency.The coating layer in the current density of 0.25 m A cm-2/0.25 m Ah cm-2,0.5 m A cm-2/0.5m Ah cm-2symmetric battery,the cycle life can reach 1300 h,the lag voltage can be as low as 30.6 m V.The average coulomb efficiency is 98.67%and 98.5%,respectively,for the asymmetric cell with the same current density after 500 cycles.（2）Ti3C2Txmaterial with two-dimensional layered structure was added into the electrophoretic solution.By adjusting the addition amount（5%、10%、15%、20%）,the composite coating with different performance was obtained.Through a large number of electrochemical tests,it was finally determined that 10%composite coating material has the best electrochemical performance.Through extensive electrochemical testing,it was finally determined that Zn@PT-10 The composite coating material has the most excellent electrochemical performance.The symmetrical battery made from this coating layer can achieve a lifespan of over 1000 h at different current densities,and the hysteresis voltage can be as low as 50.3 m V.The average coulombic efficiency was 99.45%and 99.62%for the asymmetric cells with current densities of 0.25 m A cm-2/0.25 m Ah cm-2and 0.5 m A cm-2,respectively,after 500 cycles.The full battery with sodium embedded vanadium bronze as positive electrode has A reversible capacity of 431 m Ah g-1and 73 m Ah g-1at a current density of 0.1 A g-1and 10 A g-1,respectively,and a capacity retention rate of96.67%after 1000 cycles at a current density of 5 A g-1.XRD and SEM tests were conducted on samples subjected to corrosion testing in a 2 M zinc sulfate solution and negative electrode samples before and after the production of symmetrical cycle batteries.The efficiency of the negative electrode was verified,and the calculated values of migration rate and ion conductivity also proved the superior performance of the material.The chronoamperometry test also showed that the material makes ions on the surface of the negative electrode more evenly diffused to protect the negative electrode. |
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