Insulation battery core used in battery module

Abstract

The invention discloses an insulation battery core used in a battery module. The insulation battery core comprises a common battery core and a heat dissipation protection material, wherein the commonbattery core is uniformly coated with the heat dissipation protection material. According to the insulation battery core used in the battery module, disclosed by the invention, by coating the outer surface of the common battery core with the heat dissipation protection material which takes heat conduction silicone grease as a main material, the heat conduction property of the common battery core is improved; meanwhile, the heat dissipation protection material also has the advantages of low freeness, high low temperature resistance, water resistance, ozone resistance and weathering aging resistance.

Description

technical field [0001] The invention relates to an electric core, in particular to an insulating electric core used in a battery module. Background technique [0002] At present, the global energy and environmental systems are facing enormous challenges. As a major oil consumer and carbon dioxide emitter, automobiles need revolutionary changes. The development of global new energy vehicles has reached a consensus there. In the long run, pure electric drive including pure electric and fuel cell technology will be the main technical direction of new energy vehicles. In the short term, gasoline-electric hybrid, plug-in Electric hybrids will be an important transition route. At present, the development of global new energy vehicles is facing some common problems, such as breakthroughs in key technologies, transformation of the automobile industry, infrastructure construction and consumer acceptance. [0003] At present, the surface of the electric core of the automotive power ...

AI Technical Summary

Problems solved by technology

[0003] At present, the surface of the battery cell design of the automotive power battery assembly module is made of PVC heat shrinkable sleeve. Because the PVC is thicker and softer, and the temperature resistance is lower, as the temperature rises, its surface is easy to crack and it will change under high temperature. Soft, low-temperature hardening, its molecular structure is unstable; in the whole Pack (car battery pack) design process, the module (module) design is very important, because the structural instability of PVC material will lead to the difference between the cell and the cell The tolerance range between them is too large, which leads to the structural stability of the entire module and buryes safety hazards. Considering the bumps in the driving process of the car and the mechanical vibration caused by the self-vibration of the engine, the structural stability design of Pack has become particularly important. Important, because due to the existence of mechanical vibration, if the tolerance between the cells in the module is not controlled in a reasonable range or even if the tolerance is controlled in a reasonable range in the early stage of design, due to the molecular structure of the material during use The instability of the battery leads to the change of the tolerance of the whole module. The mechanical vibration during the driving process will cause the frictional collision between the battery cell and the battery cell and the frictional collision between the battery cell and the module shell. Over time, the battery cell will cause external Short circuit, when the temperature of the cell heats up to 65 degrees Celsius, the electrolyte in it will generate gas, and the internal pressure will increase. When the internal pressure increases to a certain value, the cell will leak, and the leakage will aggravate the insulation failure of the module. Pack products at that time have no insulation safety performance at all, and even the problems caused by 18650 battery pack products will be more serious, such as fire and explosion

[0004] At the same time, the existing automotive power battery assembly module design uses barley paper and epoxy resin boards between the batteries to achieve the effect of external insulation between the batteries; the barley paper has good mechanical strength and high Electrical strength, the outer surface is smooth and tough, and the epoxy resin board has good mechanical strength, whether it is longitudinal and transverse tensile strength or bending and compressive strength, the dielectric constant is 5.5f / m, and the conventional temperature resistance is 135°C but not Direct contact with the fire source, considering that the medium between the cell and the cell must have high mechanical strength, high temperature and pressure resistance, strong insulation performance, and good thermal conductivity, and it must be self-extinguishing in the presence of flames; At present, most domestic Pack manufacturers use highland barley paper and epoxy resin board for the second external insulation between the battery cells when making modules, but because the highland barley paper has good insulation performance but does not have good heat conduction The same is true for epoxy resin boards; heat energy flows in the form of a medium and exists on the surface of objects or in the air. The way solids conduct heat is from one part of the system to another or from one system to another. It is a solid The main form of heat transfer; there is another way for solids to transfer heat, that is, heat radiation; since the temperature that the battery electrolyte can withstand is lower than 70 ° C, heat radiation transfer is not considered, mainly the form of heat conduction, that is, the object Direct contact with objects; in the module design, materials with poor thermal conductivity are used between the battery cells and the battery cells and the sheet metal parts of the module. Oxygen resin plate is used as the dielectric material between the battery core and the battery core. The insulation performance is better than other general materials, but the thermal conductivity is stretched. The battery generates a lot of heat when charging and discharging or when the car is running. If it cannot be conducted to other objects, it will cause the temperature of the battery body to rise, and then lead to a decrease in the performance of the battery. Since this is a design that cannot be compensated, it should be avoided in the early stage of the design.

At present, the biggest headache for domestic automakers is the problem related to the unbalanced internal temperature of the Pack. In the early stage of design, if a material with good insulation performance and good heat conduction performance can be used to solve this problem, of course only A small range is used to solve the problem of temperature balance. The main problem of temperature balance needs to be solved by innovations in structural performance, structure and materials.

Images