What is the limit of battery life for new energy vehicles?

1、Current battery life
From the perspective of energy conversion, the battery of an electric vehicle can be called its “heart”, which continuously converts chemical energy into electrical energy to drive the vehicle.
Take the widely used lithium iron phosphate battery as an example. Its commercial-grade cycle life is about 3,000 charge and discharge cycles. At this time, the battery capacity decay is still controlled within 20%, and under ideal conditions in the laboratory, it can exceed the 6,000 cycle threshold, which can support daily use for more than 8 years.
The theoretical life of a ternary lithium battery is 1,200 times that of a full charge and discharge, that is, the full cycle life, and the actual service life can reach about 10 years. However, the battery durability is subject to multi-dimensional constraints of driving habits, maintenance level and environmental factors, which require special attention.
Lithium iron phosphate has an advantage in safety due to the crystal stability of the olivine structure, but it comes at the cost of lower energy density (160-200Wh/kg) and larger volume mass; on the other hand, although the ternary lithium material has a high energy density of 300Wh/kg and excellent charge and discharge rate, its thermal stability is strongly related to the precision of the battery management system (BMS) and the user’s charging habits.
2、Specific influencing factors
Charging habits: Frequent use of ultra-fast charging (such as above 120kW) accelerates lithium precipitation, resulting in capacity decay (life is shortened by 20~30% when the proportion of fast charging is high).
Depth of charge and discharge (DoD): Long-term full charge and discharge (such as 100%~0%) reduces the life by more than 50% compared with shallow charge and discharge (such as 80%~20%).
Temperature environment: Long-term high temperature (>40℃) or low temperature (<-20℃) use increases the capacity decay rate by 2~3 times. Battery chemical system: Lithium iron phosphate (LFP) has a long cycle life but low energy density, and ternary lithium (NCM/NCA) has a high energy density but a relatively short life. Of course, if the manufacturer can provide high-quality warranty services, it can also extend the life of electric vehicle batteries to a certain extent. Mainstream car companies provide 8 years/160,000 kilometers of battery warranty (such as Tesla and BYD), and some brands extend to lifetime warranty (such as Weilai and Zeekr, but restrictions: first owner, non-operating vehicles).

3、Battery life judgment criteria To determine whether the battery has truly reached the end of its life, you can refer to the following judgment criteria Capacity decay: less than 70~80% of the original capacity (China’s national standard requires no less than 80%). Safety risk: significant increase in internal resistance, increased probability of thermal runaway (such as temperature difference between cells >5°C).
Function failure: The battery management system (BMS) cannot maintain the normal voltage range.
4、Future trends
With the advancement of science and technology, it is possible to extend the life of batteries in the future:
Solid-state battery: Theoretically, the cycle life exceeds 5,000 times (Toyota plans to mass produce in 2027).
Cobalt-free batteries (such as CATL NMx): reduce dependence on rare metals and improve cycle stability.
Battery self-repair technology: automatically repair electrode microcracks through electrolyte additives (laboratory stage).
In addition, Zhejiang Daily recently reported a material-lithium-rich manganese-based positive electrode material. The research team of Ningbo Institute of Materials, Chinese Academy of Sciences found that when the temperature rises, lithium-rich manganese-based cathode materials will show “negative thermal expansion” due to the reorganization of atomic structure. By using this property, people may be able to reset the “aged” battery to its “original state”, thereby achieving battery “rejuvenation”.
Of course, this material has not yet been put on the market, so it must have certain defects. The number of cycles of charge and discharge that it can withstand is relatively inferior to other cathode materials. After repeated charge and discharge, the voltage will drop sharply, which is the so-called battery “aging”.
At present, the research team is also transforming it through lithium-rich manganese-based cathode materials, hoping to design more efficient and durable lithium-rich manganese-based cathode materials. It is believed that in the near future, the range anxiety and battery life problems of new energy vehicles will be revolutionized.
5、Suggestions for extending battery life
At present, if you want the electric car to run longer, you still have to take good care of it. Here are some practical suggestions for extending battery life:
(1) Charging strategy: Keep the power between 20% and 80% for daily use (the charging limit can be set through the car computer). Perform a full cycle (10%~100%) at least once a month to calibrate the BMS.
(2) Temperature management: In high temperature environments, give priority to charging in a cool place. Preheat the battery before charging in winter (most models start automatically).
(3) Fast charging limit: Reduce the frequency of ultra-fast charging (>150kW) in non-emergency situations. It is recommended that the ratio of fast and slow charging is ≤1:3.
What is the life limit of new energy vehicle batteries? The actual service life of new energy vehicle batteries can generally reach 8~15 years, which is far longer than the replacement cycle of most users. With the advancement of battery technology and the promotion of battery replacement models (such as Weilai BaaS), life anxiety will gradually fade. Users can maximize the value of batteries through scientific use and maintenance, and in the future, it may even be possible to achieve an energy cycle model of “the body of the car is scrapped, but the battery is still in use.”