| The properties of active silver powder prepared by traditional chemical method can be satisfied with requirement of silver electrode. The electrode can only be made by manual way because it has not fluidity.It is a novel method that active silver powder prepared by sinter oxidation of silver -magnesium alloy. The silver powder not only has the properties of which made by chemical method, but also has fluidity. They can be pressed by mechanical roller to make electrode continuously. Success of the preparation of active silver powder is necessary for carrying out auto mechanical production for silver electrode.At first, orthogonal experiment was used to check influence of fusion method, oxidation temperature, mixing times and acid treatment method on properties of active silver powder. And then it was discussed particularly that influence of oxidation temperature, oxidation time and Mg content of alloy on properties of active silver powder. Statistics was applied to analyze experimental data. By comparison, we chose optimal conditions for reaction: relative Mg content was 5.5%, relative oxidation temperature was 120℃-132℃by LO air, oxidation time was 1.5h. After organic acid treatment the silver powder was set down for 24h.The result shows that silver powder exhibit better performance. It has excellent fluidity that can satisfy with mechanical rolling electrode. Activity can reach 70% upwards. Stack density was 1.1～1.25 g/cm3 and fluidity was 0.5g/s. Silver powder particle size distributed centrally so it was fit for making thin electrode. SEM was adopted to observe grains of alloy, grains after oxidation and of silver powder.Silver electrode was made to assemble batteries. Voltage and capacity have been much more improved under the same circumstance by comparing with the batteries of which electrode made by traditional method.It has been brought forth prospect of expansion for production and put forward need of elementary integrated function for automatic electrode rolling equipment.
|
PDF Full Text Request