A Comprehensive Analysis of the Lifespan of Power Batteries in New Energy Vehicles
In today's automobile market, new energy vehicles are gradually becoming the new favorites of consumers due to their advantages of environmental protection and energy conservation. The power battery, which is the core component of new energy vehicles, has always been a matter of great concern regarding its lifespan.
The power battery of a new energy vehicle is like a living organism. From the day it is born, it embarks on an irreversible path of degradation. Just like the aging process of a human being, starting from the first charge, the power battery is slowly losing its capacity. This degradation process is determined by the chemical properties of the battery cells and cannot be changed with the current level of technology. However, engineers are not helpless. They are committed to creating a favorable working environment for the batteries to prolong the degradation time of the batteries as much as possible.
I. The Impact of Years on Batteries
Even when not in use, lithium-ion batteries will experience capacity loss, that is, self-discharge. However, this degradation process is extremely slow, and consumers need not worry too much. Generally speaking, as time passes, the performance of the battery will gradually decline, but the rate of this decline is relatively slow and will not have a significant impact on daily use.
II. Cycle Life
Batteries will degrade both during use and when idle. Currently, it is generally believed in the industry that the cycle times of ternary lithium batteries are about 1500 times, while those of lithium iron phosphate batteries are around 3000 times. One cycle refers to a complete process of full charge and full discharge. When the battery capacity decays from 100% to 80%, it is no longer suitable to be used as a power battery. Because at this time, the insufficient capacity will lead to a serious shortage of the electric vehicle's cruising range, and the output voltage and current will decline, manifested as weak acceleration.
Taking ternary lithium batteries as an example, if the fully charged cruising range is 400 kilometers, calculated according to 1500 cycles, the vehicle can travel 600,000 kilometers. And it is usually difficult for household vehicles to reach this mileage. At present, the warranty period for the three major electrical systems (motor, controller, and battery) given by vehicle manufacturers is generally 8 years or 160,000 kilometers, which is a relatively conservative figure. In fact, under normal usage conditions, the power batteries of new energy vehicles can easily run for 10 years or 240,000 kilometers.
III. The Impact of Temperature on Batteries
The power batteries of new energy vehicles are extremely sensitive to temperature, and the level of temperature has a significant impact on the overall performance of the batteries, including capacity, power, charge and discharge efficiency, safety, and lifespan.
1. High Temperature Environment
When the temperature exceeds a certain range, the excessively high temperature will accelerate the progress of side reactions inside the battery. For example, the electrolyte lithium salt LiPF6 in lithium-ion batteries will undergo thermal decomposition to generate PF5, and PF5 will then undergo a hydrolysis reaction with the moisture in the electrolyte to generate HF. HF will cause the dissolution of metal in the positive electrode material, leading to the degradation of battery performance. Especially when fast charging in a high-temperature environment, it will accelerate the chemical reactions of the electrolyte and make the battery degrade faster.
2. Low Temperature Environment
In a low-temperature environment, the charge and discharge processes of lithium-ion batteries will be greatly affected. When the external load of an electric vehicle requires electricity, lithium ions will travel from the negative electrode through the separator to the positive electrode to complete the discharge process. And during charging, lithium ions will detach from the positive electrode, pass through the separator, and return to the negative electrode. However, in a low-temperature environment, due to the limited surface area of the graphite negative electrode, fast charging will cause lithium ions to crowd together, and some lithium ions will "get lost" and turn into lithium metal attached to the surface of the negative electrode, forming the "lithium plating" phenomenon. This will cause the battery capacity to decline and the electric vehicle's cruising range to decrease.
IV. How Consumers Can Maintain Power Batteries
For consumers, it is crucial to properly maintain the power batteries of electric vehicles. First of all, try to use fast charging as little as possible. Although vehicle manufacturers advertise that their vehicles can be charged to 80% in 15 minutes, fast charging comes at the cost of accelerating battery damage, especially when fast charging in a low-temperature environment. Secondly, try to avoid full charge and full discharge. The battery performance is the best within the power range of 20% - 80%. When the power is lower than 20% and higher than 80%, the charging speed will obviously decline, also because of the lithium plating phenomenon. It doesn't matter if you do full charge and full discharge a few times occasionally, but don't use it frequently.
In conclusion, the lifespan of the Power Batteries in New Energy Vehicles is affected by multiple factors such as years, cycle times, and temperature. During the usage process, consumers should pay attention to maintaining the batteries, try to reduce the situations of fast charging and full charge and full discharge as much as possible, so as to prolong the service life of the batteries and let new energy vehicles better serve our travel.
The power battery of a new energy vehicle is like a living organism. From the day it is born, it embarks on an irreversible path of degradation. Just like the aging process of a human being, starting from the first charge, the power battery is slowly losing its capacity. This degradation process is determined by the chemical properties of the battery cells and cannot be changed with the current level of technology. However, engineers are not helpless. They are committed to creating a favorable working environment for the batteries to prolong the degradation time of the batteries as much as possible.
I. The Impact of Years on Batteries
Even when not in use, lithium-ion batteries will experience capacity loss, that is, self-discharge. However, this degradation process is extremely slow, and consumers need not worry too much. Generally speaking, as time passes, the performance of the battery will gradually decline, but the rate of this decline is relatively slow and will not have a significant impact on daily use.
II. Cycle Life
Batteries will degrade both during use and when idle. Currently, it is generally believed in the industry that the cycle times of ternary lithium batteries are about 1500 times, while those of lithium iron phosphate batteries are around 3000 times. One cycle refers to a complete process of full charge and full discharge. When the battery capacity decays from 100% to 80%, it is no longer suitable to be used as a power battery. Because at this time, the insufficient capacity will lead to a serious shortage of the electric vehicle's cruising range, and the output voltage and current will decline, manifested as weak acceleration.
Taking ternary lithium batteries as an example, if the fully charged cruising range is 400 kilometers, calculated according to 1500 cycles, the vehicle can travel 600,000 kilometers. And it is usually difficult for household vehicles to reach this mileage. At present, the warranty period for the three major electrical systems (motor, controller, and battery) given by vehicle manufacturers is generally 8 years or 160,000 kilometers, which is a relatively conservative figure. In fact, under normal usage conditions, the power batteries of new energy vehicles can easily run for 10 years or 240,000 kilometers.
III. The Impact of Temperature on Batteries
The power batteries of new energy vehicles are extremely sensitive to temperature, and the level of temperature has a significant impact on the overall performance of the batteries, including capacity, power, charge and discharge efficiency, safety, and lifespan.
1. High Temperature Environment
When the temperature exceeds a certain range, the excessively high temperature will accelerate the progress of side reactions inside the battery. For example, the electrolyte lithium salt LiPF6 in lithium-ion batteries will undergo thermal decomposition to generate PF5, and PF5 will then undergo a hydrolysis reaction with the moisture in the electrolyte to generate HF. HF will cause the dissolution of metal in the positive electrode material, leading to the degradation of battery performance. Especially when fast charging in a high-temperature environment, it will accelerate the chemical reactions of the electrolyte and make the battery degrade faster.
2. Low Temperature Environment
In a low-temperature environment, the charge and discharge processes of lithium-ion batteries will be greatly affected. When the external load of an electric vehicle requires electricity, lithium ions will travel from the negative electrode through the separator to the positive electrode to complete the discharge process. And during charging, lithium ions will detach from the positive electrode, pass through the separator, and return to the negative electrode. However, in a low-temperature environment, due to the limited surface area of the graphite negative electrode, fast charging will cause lithium ions to crowd together, and some lithium ions will "get lost" and turn into lithium metal attached to the surface of the negative electrode, forming the "lithium plating" phenomenon. This will cause the battery capacity to decline and the electric vehicle's cruising range to decrease.
IV. How Consumers Can Maintain Power Batteries
For consumers, it is crucial to properly maintain the power batteries of electric vehicles. First of all, try to use fast charging as little as possible. Although vehicle manufacturers advertise that their vehicles can be charged to 80% in 15 minutes, fast charging comes at the cost of accelerating battery damage, especially when fast charging in a low-temperature environment. Secondly, try to avoid full charge and full discharge. The battery performance is the best within the power range of 20% - 80%. When the power is lower than 20% and higher than 80%, the charging speed will obviously decline, also because of the lithium plating phenomenon. It doesn't matter if you do full charge and full discharge a few times occasionally, but don't use it frequently.
In conclusion, the lifespan of the Power Batteries in New Energy Vehicles is affected by multiple factors such as years, cycle times, and temperature. During the usage process, consumers should pay attention to maintaining the batteries, try to reduce the situations of fast charging and full charge and full discharge as much as possible, so as to prolong the service life of the batteries and let new energy vehicles better serve our travel.
