12V23A battery proton exchange membrane preparation process

　　12V23A battery proton exchange membrane preparation process - the traditional method is developed on the basis of phosphate 12V23A batterys. The specific preparation process of this method is: mix the Pt/C electrocatalyst with the diluted PTFE solution (or powder) to prepare a uniformly dispersed catalyst slurry, prepare a catalytic layer on the surface of the diffusion layer by spraying, and then heat it at 80 Dry in a vacuum oven at °C to remove the organic solvent in the catalytic layer. 12V23A battery proton exchange membrane preparation process

　　(1) Clean the coating clamp. Use absorbent cotton dipped in absolute ethanol to clean the clamp and gasket (see Figure 1(a)).

　　(2) Install the proton exchange membrane on the fixture, place a sealing gasket on the base, see Figure 1(b); then place the proton exchange membrane, see Figure 1(c); then place a round hole sealing gasket. , see Figure 1(d).

　　(3) Cover the clamp panel, see Figure 1(e); then clamp the membrane with screws, see Figure 1(f); apply the prepared catalyst slurry evenly on the membrane (the membrane will curl at this time , which is a normal phenomenon), blow dry with a hair dryer, see Figure 1(g).

　　(4) Remove the membrane from the fixture, invert it, and repeat the catalyst coating step.

　　Preparation method of 12V23A battery proton exchange membrane

　　1. Traditional law

　　The traditional method was developed on the basis of phosphate 12V23A batterys. The specific preparation process of this method is: mix the pt/C electrocatalyst with the diluted pTFE solution (or powder) to prepare a uniformly dispersed catalyst slurry, use spraying to prepare a catalytic layer on the surface of the diffusion layer, and then 80 Dry in a vacuum oven at °C to remove the organic solvent in the catalytic layer. Then the diluted Nafion solution is impregnated or sprayed on the surface of the catalytic layer, and dried in a vacuum oven at 80°C; finally, the electrode and the proton exchange membrane are hot-pressed to prepare the MEA.

　　MEA prepared by this method uses pTFE as a hydrophobic agent, which is beneficial to gas mass transfer. The catalytic layer can be made thicker, about 30~50um. The disadvantage is that it is usually difficult for the Nafion solution to fully enter the catalytic layer and fully contact the catalyst. Generally, it can only penetrate about 10μm into the catalytic layer, making the catalyst utilization rate low, generally around 10% to 20%. Secondly, pTFE is used as a hydrophobic agent, which is not conducive to the conduction of electrons and protons; at the same time, the expansion coefficients of the catalytic layer and the proton exchange membrane are different. The proton exchange membrane shrinks and swells more seriously when it loses or absorbs water, and it is easy to interact with the catalytic layer. Separation causes the interface resistance of the electrode to increase and the electrical performance to decay seriously.

　　2. Thin layer electrode method

　　The Los Alamos Laboratory in the United States proposed the thin-layer electrode method, mainly to overcome the problem of expansion mismatch between the traditional electrode catalytic layer and the proton exchange membrane. The main feature of this method "is that the hydrophobic agent pTFE is not added to the catalytic layer, but the hydrophilic agent Nafion solution is used as the binder and proton conductor. The specific preparation method is: first, the diluted 5% Nafion solution and pt /C electrocatalyst is mixed, the mass ratio is about 3:1, and then water and glycerol are added to it, and the mass ratio of pt/C:H2O:glycerol is controlled at 1:5:20. After ultrasonic vibration, apply it multiple times. onto the pretreated pTFE membrane, dried at 130C, then hot-pressed the pTFE membrane with the catalytic layer and the proton exchange membrane, separated from the pTFE membrane, and transferred the catalytic layer to the proton exchange membrane. A supporting layer of carbon paper is combined with it to form a thin-layer electrode.

　　3. Vacuum deposition method

　　Vacuum deposition methods generally include chemical vapor deposition, physical vapor deposition and sputtering. The performance of electrodes prepared by vacuum deposition depends to a large extent on the preparation of the sputtered substrate, and different sputtering processes have little impact on the performance. The pretreatment of the substrate mainly involves the process of impregnating the porous substrate with pTFE and carbon powder. The sputtering method is used to make the catalytic layer, which has obvious effects on reducing the PT loading, improving the utilization of the catalyst and increasing the area specific power of the electrode. However, the water generated in the 12V23A battery prepared by this method is not easy to discharge, and it It is not suitable for mass production of electrodes and the cost is also high.

Read recommendations:

R03P

Can lithium battery manufacturers popularize the component performance of lithium power batteries?

Standard conditions for lithium-ion battery industry

18650 lithium battery cells

D USB 1.5V 6000mWh