In the power battery segment, Ding Yonghua, deputy dean of the research institute of Guangzhou Penghui Energy Group (hereinafter referred to as Penghui Energy), delivered a keynote speech on "Analysis of Potential Risks in Power Battery Modules and System Safety". A wonderful analysis was carried out from two perspectives of safety and system safety.

　　The differentiation of power battery modules will also lead to the phenomenon of circulating current. Low-capacity & high-resistance batteries will be in different states during charging and discharging. For example, the platform voltage is always lower than other batteries during discharge, external discharge cycles, parallel internal charging cycles, and batteries The performance drops faster, and the risk of internal short circuits increases.

　　So, how to solve this problem? The method proposed by Ding Yonghua is to optimize the battery health assessment strategy and improve the sensitivity of abnormal diagnosis to detect abnormal battery modules in a timely manner.

　　In terms of power battery system safety, shell protection, battery module connection, thermal management, and fire-fighting devices will also bring potential risks to the battery.

　　Take the previous Tesla ModelS hitting a tow bar scattered on the road as an example. The huge impact force caused the tow bar to pierce the chassis armor of the battery pack, and eventually the battery was damaged and caught fire. This also exposes the protection problem of the power battery shell.

　　In fact, as one of the core components of new energy vehicles, the power battery system has its own protection and management specifications. For example, the physical protection of the shell should be protected by the car body bracket protection and the battery box protection. Stainless steel or anti-rust fasteners will be used inside the power battery system.

　　However, the fasteners inside the battery use many types of metal materials. During use, as the ambient temperature changes, the coefficient of thermal expansion is different, continuous vibration and self-heating will cause looseness and poor contact.

　　In response to the above problems, Ding Wenhua proposed solutions from two aspects: battery materials and thermal management systems. For battery materials, improve the stability of the cathode material, SEI membrane, and electrolyte to reduce heat-induced heat generation and heat generation rate. At the same time, the decomposition of SEI film is the key to controlling internal thermal runaway and reducing the probability of thermal runaway chain reaction.

　　In the thermal management system, the power battery management must meet the IP67 protection level standard stipulated by battery safety, including an insulation layer to reduce the impact of the external environment temperature on the battery system; secondly, the heat dissipation methods such as convection, radiation, and heat conduction should be strengthened in the unit time. Controllable management of battery system temperature is also a great way.