A battery system and its assembly method

Abstract

The invention belongs to the technical field of batteries, and discloses a battery system and an assembling method thereof. The battery system includes a composite phase-change material and a battery; the composite phase-change material includes a phase-change material and an olefin block copolymer; and an interference fit is used between the composite phase-change material and the battery. The composite phase change material used in the present invention includes a phase change material, such as paraffin wax, and an olefin block copolymer, wherein the olefin block copolymer is a supporting material, which can achieve thermal flexibility and prevent leakage of the liquid phase change material. The composite phase change material and the battery are assembled by means of interference fit, which greatly reduces the contact thermal resistance between the battery and the composite phase change material, greatly reduces the temperature during the working process of the battery, and not only improves the electrical performance of the battery during the working process. , but also significantly improve the safety of battery use.

Description

technical field [0001] The invention belongs to the technical field of batteries, and particularly relates to a battery system and an assembling method thereof. Background technique [0002] Li-ion batteries are widely used in electrochemical energy storage systems as energy storage devices due to their advantages in key performance such as energy density and operating voltage. The working mechanism and performance of the battery show a high dependence on temperature, and maintaining the battery within a suitable temperature range can maintain the optimal working performance. The battery will generate a certain amount of heat during the working process, so it is necessary to discharge the heat reasonably to avoid heat accumulation and affect the battery voltage, charge and discharge efficiency, cycle life and the safety of the battery. [0003] The battery thermal management system based on the phase change material can effectively control the working temperature of the bat...

AI Technical Summary

Problems solved by technology

The thermal conductivity of paraffin (PA) is about 0.2W m -1 ·K -1 , and will become liquid when the temperature is higher than the melting point, there is a serious leakage problem

In addition, the battery installation and integration problems caused by the rigidity of phase change materials will lead to high thermal resistance at the contact interface with the battery. If the thermal resistance is too high, the operating temperature of the battery will be too high, which will not only affect the performance of the battery, but also pose a great safety hazard. Hidden danger

In particular, for cylindrical batteries, it is difficult to effectively match the curved surface characteristics with phase change materials

The existing related assembly method is to first open a hole slightly larger than the outer diameter of the battery on the bulk phase change material, and then insert the battery into the hole, but in this way, the battery and CPCM (CPCM is a composite phase change material, is It is made by blending fatty acid esters and advanced aliphatic alcohol phase change materials at a mass ratio of 95:5), and there is no close contact between them, so there is inevitably a large thermal resistance

Thermally conductive adhesive can be filled in the pores, but still suffers from uneven coating, increased space and economic costs

For prismatic batteries, when cooperating with phase change materials, in order to compress the phase change materials and batteries, the same compression device is often used to form a unit with a large number of batteries. However, the energy density of prismatic batteries is large. When a thermal safety accident occurs to one of the batteries, it will affect a large number of other batteries through heat transfer, and the hazard will be greatly increased.

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