Introduction to the pretreatment of nickel foam

Nickel foamis a material used for making battery electrodes, and the production process of ordinary nickel Foam material is as follows: the polyurethane sponge is first conductivized, then electrodeposited, and finally sintered.

In the above steps, the conductive treatment generally includes chemical plating, coating conductive adhesive, and vacuum plating in three ways; the electrodeposition can be sulfate or sulfamate nickel plating; the existing sintering process is first completed by air burning off the polyurethane sponge, and then reducing and sintering the sponge under a hydrogen reducing atmosphere in two steps, wherein the air burning off the polyurethane sponge is oxidized and decarbonized at a temperature of 300 to 700°C. The sintering process is completed by air burning off the polyurethane sponge, and then reducing and sintering the polyurethane sponge in a hydrogen reducing atmosphere; The reduction treatment is performed under hydrogen reduction atmosphere at a temperature of 800 to 1000°C for 30-60 minutes, and the reduction atmosphere is ammonia decomposition gas, and the amount of decomposition gas consumed is 0.8-1.2 L/g (each gram of nickel requires 0.8-1.2 liters of ammonia decomposition gas to be consumed)

Improved method of making nickel foam, the step of which comprises conductivization, electrodeposition and sintering of a polyurethane sponge, characterized in that said sintering step is to pyrolyze and sinter the polyurethane foam directly in a reducing atmosphere after electrodeposition, wherein the reducing atmosphere is ammonia decomposition gas, the reducing temperature is 400-1000° C., the reducing time is 30-60 minutes, and the amount of decomposition gas consumption is 0.4-0.8 L/g. (Each gram of nickel needs to consume 0.4-0.8 liters of ammonia decomposition gas.) The ammonia decomposition gas is a mixture of nitrogen and hydrogen, and the volume ratio of nitrogen and hydrogen is 1:3.

The reaction mechanism is that after electrodeposition of nickel foam containing polyurethane sponge directly in the hydrogen reduction atmosphere pyrolysis sintering, where the carbon and hydrogen action, generating CH4, C2H6 and other gaseous hydrocarbons, the above gasification process is sufficient to remove the graphite C in the porous body cleaner.

It effectively solves the existing shortcomings in the existing technology of nickel foam in the sintering process, such as easy to crack, deformation arching, low yield, high energy consumption, nickel foam mechanical properties are not stable.