What safety problems should be paid attention to the production of lithium batteries

It was first used in cardiac pacemaker. The self-discharge rate of lithium battery is very low and the discharge voltage is flat. It enables the implanted pacemaker to operate for a long time without recharging. Lithium batteries generally have a nominal voltage higher than 3.0 volts, which is more suitable for integrated circuit power supply. Manganese dioxide batteries are widely used in calculators, digital cameras and watches.

In order to develop more excellent performance of varieties, people of various materials were studied. To create an unprecedented products. For example, lithium sulfur dioxide battery and lithium thionyl chloride battery is very characteristic. Their positive active material and electrolyte solvent. This structure only in non-aqueous solution of electrochemical system. So, Lithium electricity Pool research, also promoted the development of non-aqueous system electrochemical theory. In addition to use a variety of nonaqueous solvents, people also has carried on the research of polymer film battery.

Sony in 1992 successfully developed Lithium ion batteries. Its practical application, make people's mobile phone, notebook, calculator carry type electronic equipment such as less weight and volume. Use time greatly extended. Because do not contain heavy metal cadmium in lithium ion batteries, compared with the nickel cadmium battery, greatly reduce the pollution to the environment.

The safety problems in the process of lithium battery production

Had better use the high viscosity adhesive glue, and make sure the adhesive is fully dissolved and adhesive is fully dry, water content control of NMP, when dissolved adhesive, best can heating, dissolving, more fully enhance adhesive bonding effect. If interested in water system of adhesive, can consider to Chengdu Yin le (LA132), if use water-based adhesive, bonding problem doesn't exist, but the vacuum baking temperature and time need to be extended appropriately.

To ensure that the lithium iron phosphate material and conductive material drying, had better be in 100-120 degree within the vacuum oven bake more than 2 hours, and down to room temperature, add in more PVDF solution.

Pay attention to ingredients workshop humidity, due to the reason of the circulating water, humidity is more difficult to control, thus recommended charging time as far as possible control in a relatively short period of time, and it is best to control the humidity below 30% RH.

Slurry agitation strength, it is better to use high energy shear emulsifying dispersion, or colloid mill, ensure fully dispersed and paste viscosity and liquidity, the viscosity of the slurry best adjustment in 5000-6000. Second, liquidity is a pulp can glue good premise, slurry liquidity much affected by the moisture, if the pulp a jellylike (into gel), on the performance of PVDF decline, generally difficult to do processing, so strong moisture control is very important in the process of mixing.

Due to material lithium iron phosphate coating speed is slow, when slurry coating may have some changes, especially when the humidity is bigger, affect material bonding effect, therefore, paste in relatively airtight container for the best good or partial transfer material.

Pole piece after coating and drying, the best production, if need to deposit a period of time in production, the best vacuum baking preserved. After the completion of the production, baking temperature should be set at 100 degrees, vacuum bake for about 10 h, not too long, too long to chip.

Winding or fold were most in need of attention is the control of the dust, especially on electrode bonding effect is not ideal, need more attention, otherwise it is easy to produce low voltage problem. Coiling should also pay attention to the battery assembly than batteries, the best control under 91%, otherwise, the assembly is bigger than too easy to cause the battery low voltage.

Battery baking suggested above 85 degrees bake for 24 hours, if using single-layer PE membrane, can be appropriate to reduce the temperature, but time must be guaranteed, and regularly take a breath.

Battery liquid injection rate control in 4 g/Ah, liquid injection should be put on hold after 7 hours, it is better to high temperature (50 degrees) on aging.

Into, it is best can use 0.05 c ratio charging 2 hours, 0.1 c charging five hours, 0.2 c constant current constant voltage charging more than 4 hours, on-line voltage at around 3.8 v (into voltage can be relatively a bit higher for the first time), 0.2 c discharge to 2.3 v.

Points when, had better use 0.2 c inflation (in order to improve the efficiency is also can use 0.5 c or 1 c put charging, charging and discharging voltage controlled between 3.8 v to 3.8 v.

Battery capacity if there is a bottom or low voltage platform, can consider to high temperature activation (65 ° c) more than two hours after the second (0.1 c) filling small current, conducts regular points again.

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