The popularity of new energy vehicles, ternary lithium battery power Battery the performance of the mainstream choice has attracted much attention. Especially in northern China, the winter temperature is as low as tens of degrees below zero. Extreme cold environment poses severe challenges to the performance and safety of lithium batteries. Many users care about "can ternary lithium batteries be used in winter in the North?" This article will focus on the applicability of ternary lithium battery in northern winter, analyze its performance, existing problems and countermeasures to help consumers better understand and use ternary lithium battery.

I. Review of basic characteristics of ternary lithium batteries

ternary lithium battery (NCM or NCA system) is a lithium ion battery with nickel, cobalt, manganese or aluminum as the cathode material, because of its high energy density and long cycle life, the cost is relatively moderate and widely used in the field of electric vehicles. Compared with traditional lithium iron phosphate batteries, ternary lithium batteries have higher energy output per unit weight and can provide longer endurance mileage.

However, the material characteristics of ternary lithium battery also determine that it is sensitive to ambient temperature, especially in low temperature environment, the internal chemical reaction rate of the battery slows down, resulting in the decrease of output power and capacity.

II. Influence of low temperature environment in northern winter on ternary lithium battery

the winter temperature in the North is usually lower than zero, and some areas can reach minus 20℃ or even lower. This wayThe impact of the environment on the ternary lithium battery is mainly reflected in the following aspects:

1. Obvious capacity attenuation

under the condition of low temperature, the viscosity of electrolyte inside the battery increases and the migration speed of lithium ions slows down, resulting in a sharp decrease in the available capacity of the battery. Generally speaking, when it is minus 20℃, the capacity loss of ternary lithium battery can reach 30%-50%. This means that the mileage is significantly shortened, affecting the user experience.

2. The internal resistance increases and the dynamic performance weakens.

The cold environment leads to the increase of the internal resistance of the battery, the voltage drops faster when the battery is discharged, and the power output is limited. Vehicles may feel insufficient power when starting or accelerating, especially under high load conditions such as rapid acceleration and climbing.

3. Reduction of charging efficiency and potential safety hazards

in the low temperature state, the speed of lithium ion embedding into the negative electrode during the charging process of the battery is slow, which is easy to form lithium metal crystals on the surface of the negative electrode and has potential safety hazards. In addition, prolonged low-temperature charging time and reduced charging efficiency may lead to insufficient battery charging.

4. Impact of cycle life

frequent use in low temperature environment without effective heat preservation measures will aggravate the aging of battery internal materials and shorten battery life.

3. Can ternary lithium battery be used normally in northern winter?

To sum up, there is a certain performance decline in the use of ternary lithium batteries in winter in the north, but it does not mean that they cannot be used. In fact, most electric vehicles equipped with ternary lithium batteries have designed corresponding low temperature management measures to enable them to operate normally in winter in the north.

1. Battery thermal management system (BMS)

modern electric vehicles are generally equipped with battery thermal management system. The battery temperature is adjusted by Heater, liquid cooling or air cooling system to ensure that the battery is maintained in a suitable working temperature range. Especially in winter, the battery pre-heating function can raise the battery temperature before the vehicle starts, reducing the performance attenuation caused by low temperature.

2. Optimization of charging strategy

when the vehicle is at low temperature, the current limiting charging strategy is usually adopted to reduce the charging current and avoid the formation of branches. At the same time, some vehicles support charging pile heating to improve charging efficiency and safety.

in winter, reasonable driving habits and charging habits are helpful to reduce the influence of low temperature on ternary lithium batteries. For example:

• avoid parking for a long time in extremely low temperature environment, and try to choose a covered or indoor parking lot when parking.
• Try to keep the battery power between 20% and 80% to prevent over-discharge or over-charging.
• After starting, wait for the battery to warm up properly to avoid rapid acceleration of high load.

IV. Precautions for using ternary lithium batteries in northern winter

in order to maximize the performance and life of ternary lithium battery in winter, users and manufacturers should pay attention to the following points:

1. Keep the battery temperature

battery temperature is the key factor affecting performance. The vehicle should be equipped with perfect battery heating and temperature surveillance system to avoid battery supercooling. Users should minimize long-term parking in extremely cold environment.

2. Reasonable charging

avoid fast charging at low temperature and adopt slow charging or constant current charging mode to reduce safety risks. The battery preheating function can be used before charging to improve the charging efficiency.

3. Monitor battery status

regularly check the battery management system prompts, pay attention to the battery temperature, voltage, current and other states, and find abnormalities in time to avoid damaging the battery.

4. Vehicle maintenance

do a comprehensive inspection for the vehicle in winter to ensure that the battery thermal management system and electrical system work properly and improve the safety and stability of winter use.

Ternary lithium batteries do encounter problems such as capacity decline, power weakening, and charging efficiency reduction in the low temperature environment in winter in the north. However, through advanced battery thermal management technology and reasonable use and maintenance, the ternary lithium battery can fully cope with the cold winter and meet the daily travel needs. Users should pay attention to the battery temperature management and charging mode of vehicles in cold seasons to avoid extreme operation, prolong battery life and guarantee driving safely.