How to improve the low temperature performance of lithium iron phosphate ion battery pack?

　　Author ：Iflowpower – Portable Power Station Supplier

It's cold, how to improve the lithium phosphate ion battery pack low temperature performance? It is now fast to October, and the temperature will begin slowly, which is a test for lithium iron phosphate ion battery packs. It is well known that the high temperature performance of the lithium-ion battery pack is excellent, and the hot peak can reach 350 ~ 500 ¡ã C, and 100% capacity can still be released in the case of high temperature (60 ¡ã C). But low temperatures are worse than other battery systems, so how to improve their low temperature performance? Lithium phosphate ion battery: lithium phosphate ion battery refers to a lithium ion battery with lithium iron phosphate as a positive material.

The positive electrode material of the lithium-ion battery is important for lithium cobalt organte, lithium manganate, lithium nickel acid, three-dimensional material, lithium iron phosphate, etc. Among them, lithium iron phosphate is a positive material currently used in most lithium-ion batteries. Lithium iron phosphate ion battery pack needs to increase, improve lithium battery low temperature performance.

What is the factor affecting the low temperature energy of lithium iron phosphate ion battery pack? In response to the lithium iron phosphate ion battery pack, industry experts have made more detailed research on its low temperature characteristics, the reasons are as follows: 1. Production environment: lithium iron phosphate ion battery packs are made as a chemical raw material, complicated high-tech products The production environment has high requirements for temperature, humidity, dust, etc., if there is no control in place, the battery quality will fluctuate.

2, poor conductivity, slow lithium ion diffusion speed. When high-rate charge and discharge, the actual amount is low, this problem is a difficult point to restrict the development of lithium iron phosphate industry. Lithium iron phosphate does not have a wide range of applications so late, this is an important issue.

3, the impact of the material, the lithium iron phosphate positive electrode itself is relatively poor, and the polarization is relatively prone to polarization, reducing the capacity of the capacity; the negative pole is important to high temperature charge, because it affects the security problem; One, may increase the viscosity at low temperature, the lithium ion migration impedance will increase; the fourth is the binder, and this is also relatively large. How to improve lithium iron phosphate ion battery pack low temperature performance? We raise low temperature performance of lithium iron phosphate ion battery pack from the positive electrode, negative electro-hydraulic, and binder. In terms of positive, it is now nanomechanically, its particle size, resistance, and AB planar axis growers will affect the characteristics of the entire battery low temperature.

Different processes have different effects on the positive electrode, and the low temperature discharge characteristics of the battery made by 100 to 200 nano-particle diameter phosphate, which can release 94% at -20 degrees, which is the particle diameter of nanofence shortening the path of the migration, It also improves the performance of low temperature and discharge, because the lithium phosphate discharge is related to the positive electrode. Considering charging characteristics from the negative electrode, the low temperature charging of lithium ion batteries is important, including the particle size of the particle size and the pitch of the negative electrode, select three different artificial graphite as an negative electrode to study different layer spacing and particle size pair low temperature Effect of characteristics. From three materials, the grain graphite of the layer is large, from impedance, the body impedance and ion migration impedance are relatively small.

In terms of charging, the lithium-ion battery pack is not large at low temperature in winter, and it is important that low temperature charge. Because in horizontal flow ratio, 1C or 0.5C cross-flow ratio is very critical, to constant pressure to be very long, by improving three different graphite comparisons, one of which is relatively large in -20 degree charging constant flow ratio Improved, from 40% to 70%, the increase in the layer spacing, there is also a decrease in particle size.

This piece of the electrolyte, in -20 degrees, -30 degrees, the electrolyte, increased viscosity, and deteriorate the performance. Electrolyte from three aspects: solvent, lithium salt, additive. The solvent has a low temperature effect of lithium iron phosphate ion battery packs from 70% to more than 90%, with more than a dozen points; second, different lithium salts have a certain impact on the characteristics of low temperature charge and discharge.

We fixed the solvent system and the lithium salt foundation, the low temperature additive can increase the discharge capacity from 85% to 90%, that is, in the entire electrolytic liquid system, solvent, lithium salt and additives are low temperature for our power lithium battery. Features have a certain impact, including other material systems. Adhesive, in case of 20 degrees, the two points are probably processed by 70 to 80 cycles, and the entire plate is the status quo of the adhesive failure, and the linear binder does not exist.

this problem. After the entire system, after the improvement of the positive electrode, the negative electrode, the electrolyte to the binder, the lithium phosphate ion battery monomer does better effect, one is charging characteristics, -20, -30, -40 degrees Temperature 0.5C charging constant current ratio can reach 62.

9%, - 20 degree temperature discharge can be released 94%, this is some of the characteristics of the magnification and cycle.