Choosing the right battery separator is crucial to the performance and safety of the battery. Here are some factors to consider when choosing a battery separator:

Separator is an important part in battery production, its quality directly affects the discharge capacity and service life of charge-discharge cycle of battery, so we must pay attention to the selection and research of battery separator. In general, the quality requirements of the partition should have the following requirements.

Lead-acid batteries are mainly composed of negative elemental lead, positive lead dioxide, electrolyte and separators. The PE separator is between the positive and negative plates of the battery, which can prevent the positive and negative plates from directly contacting and discharging to cause short circuit. At the same time, there are a certain amount of holes on the separator to ensure the passage of positive and negative ions and prevent open circuit. Therefore, the importance of the separator is no less than that of the positive and negative plates of the battery. At present, it is generally believed that the explosion accident caused by the short circuit of the lead-acid battery is mainly caused by the aging of the separator.

Maintenance free battery means that it is not required to be overhauled and maintained from the time of delivery to the time when it is in the hands of users until the end of its service life. The maintenance free battery is a sealed single battery and cannot be disassembled. What are the reasons for maintenance free lead-acid batteries?

1. Compared with many traditional separators, PE separator has the strongest oxidation resistance from the material point of view. However, due to its soft texture and thin base thickness, PE separator is deformed during battery charging and discharging, which is easy to cause heat loss and aggravate the thermal oxidation process of the separator.

PE battery separator has many effects on the performance of lead battery. Every improvement of separator quality is accompanied by the improvement of lead battery performance. The main function of PE battery separator is to prevent short circuit between positive and negative electrodes, but it cannot significantly increase the internal resistance of the battery. PE battery separator is mainly used to prevent short circuit between positive and negative electrodes, but it cannot significantly increase the internal resistance of the battery. Therefore, the separator should be porous, allowing free diffusion of electrolyte and ion migration, and has a relatively small resistance. PE battery separator shall not reach the opposite electrode plate through fine holes, that is, the hole diameter shall be small, the number of holes shall be large, and the total area of the gap shall be large.

The quality of the separator will directly affect the capacity, charge-discharge cycle life and self-discharge performance of the battery. The analysis results of the battery show that the main reason for the low cycle life of the battery is that the diaphragm with poor quality has a relatively large pore size, and the pore size distribution and thickness are not uniform, so as the charging and discharging progress, the positive lead powder gradually penetrates a small amount The separator goes to the side of the negative electrode, and the negative lead dendrite may penetrate the separator and eventually cause a chronic short circuit of the battery.

Structure and properties of ultra-fine glass fiber separators This kind of separator is composed of ultra-fine glass fibers with a diameter of 0.5~4um without any organic binder. The non-compressed glass fiber paper is made by the papermaking method, and its structure is multi-layered mat-like, and relatively small and high labyrinth free channels are formed by disordered glass fibers. The separator has significantly better performance than ordinary battery separators in many aspects.

In the 1950s, starting batteries mainly used wooden separators. Because they had to be used in wet conditions, the negative plates were easily oxidized, and the initial charging time was long, and they could not be used for dry-charged lead batteries. In particular, wooden separators are not resistant to oxidation and corrosion in sulfuric acid, resulting in short battery life. In order to improve the life of lead-acid batteries, it is proposed to use wood separators and glass wool as separators, which doubles the life of the battery, but the internal resistance of the battery increases, which has an adverse effect on the battery capacity and starting discharge, and can also meet the standard requirements at that time.

Ultra-fine fiberglass separator At present, ultra-fine glass fiber separator (AGM) is commonly used in VRLA batteries. The wettability is the main characteristic of the separator capable of adsorbing the maximum amount of electrolyte. The separator must have long-term stable chemical and electrochemical corrosion resistance in the battery, it must not release any substances that increase the gas evolution rate, corrosion or self-discharge, and it must have good tensile strength to ensure that the separator is in the battery. will not be punctured by sharp edges or small particles during production assembly.

The separator is an important component of the battery and is not an active substance. In some cases it even plays a decisive role. The material itself is an electronic insulator, and its porosity makes it ionically conductive. The resistance of the separator is an important performance of the separator, which is determined by the thickness of the separator, the porosity, and the degree of tortuosity of the hole, and has an important influence on the capacity and terminal voltage level of the high-rate discharge of the battery; The stability of the separator in sulfuric acid directly affects the life of the battery; The elasticity of the separator can delay the shedding of the positive active material; the pore size of the separator affects the short-circuit degree of lead dendrites. Due to the various effects of the separator on the performance of the lead-acid battery, every improvement in the quality of the separator is accompanied by the improvement of the performance of the lead-acid battery.

The time required for the PvC separator, PE separator, rubber separator, and PP separator to achieve stable resistance is different. This is mainly due to the different main materials used for the separator, and the different time it takes for the separator to be completely wetted by the sulfuric acid solution. Different ratios and apertures, the PP separator takes the shortest time to stabilize the resistance, the PE separator takes the longest time, the PVC separator and the rubber separator are in the middle, and the PVC separator takes a slightly shorter time than the rubber separator.