What Are the Causes of Battery Degradation in New Energy Vehicles?
2 Answers
Battery degradation in new energy vehicles is an unavoidable phenomenon; as long as the battery is in use, degradation will inevitably occur. Additionally, different usage habits among vehicle owners can have varying impacts on the battery pack. There are two main scenarios for battery degradation in new energy vehicles: lithium battery abuse and temperature factors. When the State of Charge (SOC) is below 120%, lithium batteries do not exhibit significant capacity loss. However, at excessively high SOC levels, the decomposition rate of the electrolyte accelerates, forming a thick deposition layer on the graphite anode. This layer contains lithium in a precipitated form. Temperature is one of the critical factors affecting the lifespan of lithium batteries. Both excessively high and low temperatures can reduce the content of active lithium ions, damage the structure of electrode materials, and cause metal ion dissolution, leading to severe battery capacity degradation. Precautions for Using New Energy Vehicle Batteries: Do not use the battery in environments where the temperature exceeds 60°C. Excessive temperatures can cause heat dissipation issues in the power battery, motor, and control systems, leading to system fault codes. In severe cases, this can result in short circuits and pose a fire risk. Many electric vehicle fires are caused by inadequate thermal management systems or operational errors. Avoid exposing the battery pack to water. Although battery packs have a certain degree of waterproofing capability—typically meeting the IP67 waterproof rating standard—there is no guarantee they will remain completely watertight. During vehicle water crossings, water pressure can build up, increasing the likelihood of water ingress due to pressure differences. Water ingress can render the battery inoperable and may cause internal short circuits, posing significant risks. If the vehicle experiences a strong collision while driving, park in a safe area and inspect the vehicle's chassis wiring and battery pack area for damage. If any damage is detected, it is not advisable to continue driving. Contact a service station for assistance immediately.
As a long-time professional researcher in electric vehicles, I believe the primary cause of battery degradation in new energy vehicles is the gradual deterioration of the internal chemical structure of lithium-ion batteries. During normal usage, charge-discharge cycles lead to the migration and loss of active materials between the positive and negative electrodes, naturally reducing capacity. The more cycles performed, the more pronounced the degradation becomes—for instance, each deep discharge accelerates this process. Temperature is also a critical factor; exposure to high temperatures speeds up chemical reactions, causing irreversible damage, which is particularly common when parking in hot summer conditions. Additionally, improper charging habits, such as frequent use of fast charging or keeping the battery at full charge for extended periods, can shorten battery life. I recommend that vehicle owners develop good habits, such as avoiding exposure to extreme temperatures, maintaining charge levels between 20% and 80%, and conducting regular battery health checks. These practices can effectively slow degradation, improving both driving safety and cost efficiency. Don’t overlook this—severe degradation can also impact the vehicle’s range, causing inconvenience in daily driving. Early maintenance is key.
