High-temperature nickel-metal hydride battery diaphragm

Abstract

The invention relates to a high-temperature nickel-metal hydride battery diaphragm. The diaphragm is prepared through the processes that nonwoven fabric base cloth prepared from polyolefin complex fibers and thermostable fibers is grafted with acrylate and / or sodium p-styrenesulfonate through radiation, and then hot rolling and shaping are carried out. Thermal shrinkage caused when the diaphragm encounters high temperatures in the processing and using processes can be effectively reduced, and the diaphragm can maintain high air permeability in the use process.

Description

【Technical field】 [0001] The invention relates to the field of nickel-hydrogen batteries, in particular to a diaphragm suitable for a sealed high-temperature nickel-hydrogen battery. 【Background technique】 [0002] It is well known that the key materials constituting a nickel-metal hydride battery include positive and negative electrode materials and diaphragm materials. Among them, since the diaphragm is a special material used to separate the positive and negative electrodes of the battery, it not only makes the redox reactions on the positive and negative electrodes in different regions In order to prevent the positive and negative active materials from contacting each other, but also to allow the free diffusion of the electrolyte and ion migration to generate current, therefore, the quality of the separator will have a greater impact on the performance of the nickel-metal hydride battery, especially For high-temperature Ni-MH batteries, the quality of the diaphragm direc...

AI Technical Summary

Problems solved by technology

[0003] Generally, high-temperature Ni-MH batteries refer to batteries that can work at an ambient temperature above 45°C. Since the charge and discharge performance of ordinary Ni-MH batteries will decrease significantly when the ambient temperature exceeds 30°C, it is generally It is believed that the charge and discharge capacity of high-temperature Ni-MH batteries under high-temperature conditions should reach more than 80% of that under normal temperature conditions; The treated polyolefin fibers are prepared by wet-laid non-woven fabrics. However, a large number of practices have proved that traditional nickel-hydrogen battery separators cannot be effectively applied to high-temperature nickel-hydrogen batteries. The main reason is that the separator is processed And during use, heat shrinkage will occur when the temperature is above 80°C, resulting in a decrease in the porosity of the diaphragm, a smaller pore size and a decrease in air permeability;

[0004] On the other hand, when high-temperature Ni-MH batteries work under high-temperature conditions, the hydrogen and oxygen produced by water electrolysis in the later stage of charging are much higher than ordinary Ni-MH batteries. For sealed Ni-MH batteries, the resulting These gases need to pass through the diaphragm to recombine into water, otherwise the internal pressure of the battery will increase. Once the gas overflows, the electrolyte will be lost, which will eventually deteriorate the battery performance and cycle life. Therefore, the diaphragm of high-temperature Ni-MH batteries is It is necessary to maintain a high air permeability under high temperature conditions, but it is difficult for traditional nickel metal hydride battery separators to meet this condition