Compound nylon diaphragm, and manufacturing method

Abstract

The diaphragm is a hot melted and rolled product from non-woven fabrics of nylon backing material in one, two or three layers. In total weight of raw fiber, nylon fiber is in 40-60 wt%, and hot melted composite fiber with dual constituents in low melting point is in 40-60 wt%; or, nylon fiber is in 40-60 wt%, hot melted composite fiber with dual constituents in low melting point is in 30-45 wt%, superfine vinylon fiber is in 10-15 wt%. The method includes steps: using different techniques prepares non-woven fabrics of nylon backing material in different structures; using hot rolling machine with three rollers rolls non-woven fabrics of nylon backing material in one, two or three layers. Features are: simple method, small investment easy of obtaining materials and low cost. The diaphragm is accorded with requirements of nickel cadmium SC cell: high capacitance 1500man-2000man, and discharging in 10C-15C high multiplying factors.

Description

technical field [0001] The invention belongs to the technical field of battery diaphragms, and relates to a composite nylon diaphragm and a manufacturing method thereof, which are particularly suitable for use as diaphragms of secondary alkaline batteries such as nickel-cadmium batteries and nickel-cadmium SC batteries. Background technique [0002] Nickel-cadmium (Ni / cd) batteries have excellent characteristics of fast charging and high-current discharge, and are widely used as power sources for cordless electric tools, called Ni-cadmium SC batteries. Its high current and high rate discharge performance cannot be replaced by other rechargeable batteries. In the battery, the role of the separator is to: isolate the positive electrode and the negative electrode to prevent them from short circuit; absorb and store the electrolyte; act as a channel for the gas generated by the chemical reaction when the electrode is charged and discharged. Therefore, there are high technical r...

AI Technical Summary

Problems solved by technology

Therefore, this vinylon fiber separator cannot be used for high-capacity (1500man-2000man) and high-rate discharge (10C-15C) nickel-cadmium SC batteries that are currently in great demand in the market, and can only be used for ordinary nickel-cadmium low-capacity, small Current charge and discharge battery

In CN1656630A "non-woven fabric for alkaline battery diaphragm and its manufacturing method", it is disclosed that 60-95wt% of aromatic polyamide fiber and 5-40wt% of ethylene-vinyl alcohol copolymer fiber are used as bonding fibers, and the wet method is used to manufacture Although the non-woven fabric for the separator can meet the requirements of ultra-high capacity and ultra-high rate discharge of nickel-cadmium batteries, because the separator contains a high proportion of semi-aromatic fibers, although its hydrophilic liquid retention ability has been improved, but in In the high temperature state of the battery, there will still be ammonia precipitation, which will accelerate the self-discharge phenomenon of the battery, that is, the charge retention capacity of the battery will decrease; in addition, the raw materials for manufacturing the separator: semi-aromatic polyamide fiber, ethylene-vinyl alcohol copolymer fiber, The high price makes the cost of the separator greatly increased. For the high-capacity nickel-cadmium battery with a large market demand, it is difficult to accept the high price of the separator, and these raw materials are not commercially available industrial products, and are not easy to obtain.