How to prevent electric scooter batteries from being damaged at extreme temperatures?

How to prevent electric scooter batteries from being damaged at extreme temperatures?

1. Battery temperature management technology

1.1 Thermal management system design
Electric scooter batteries are prone to performance degradation or even damage at extreme temperatures, so the design of the thermal management system is crucial. The main function of the thermal management system is to maintain the battery within a suitable operating temperature range by dissipating heat or heating, thereby extending the battery's service life and improving its performance.
Heat dissipation design: In a high temperature environment, the battery will generate a lot of heat, and the heat dissipation design can effectively dissipate this heat. Common heat dissipation methods include natural heat dissipation, forced air cooling, and liquid cooling. Natural heat dissipation mainly relies on heat exchange between the battery casing and the surrounding air to dissipate heat. This method is low in cost, but the heat dissipation efficiency is limited. Forced air cooling uses a fan to discharge hot air, which has a high heat dissipation efficiency, but it will increase the energy consumption and noise of the electric scooter. Liquid cooling uses coolant to circulate around the battery to remove heat, which has the best heat dissipation effect, but the system is complex and costly. For example, some high-end electric scooters use a liquid cooling system, and the temperature control accuracy of their batteries in a high temperature environment can reach ±5℃, effectively preventing the battery from being damaged by overheating.
Heating design: In low temperature environment, the performance of the battery will be seriously affected. The heating design can increase the temperature of the battery to keep it within the normal operating temperature range. The main heating methods are electric heating and chemical heating. Electric heating converts electrical energy into thermal energy through the heating element inside the battery. The heating speed is fast and the control accuracy is high, but it consumes a certain amount of electricity. Chemical heating uses the heat generated by chemical reactions to heat the battery. This method does not require an additional power supply, but the heating speed is slow and difficult to control. For example, a certain electric scooter uses an electric heating system. In an environment of -20℃, the battery can be heated to above 0℃ within 15 minutes, which effectively improves the low temperature performance of the battery.

1.2 Application of phase change materials
Phase change material (PCM) is a material that can absorb or release a large amount of heat during the phase change process. Applying it to the temperature management of electric scooter batteries can effectively alleviate the temperature changes of the battery at extreme temperatures and play a good protective role.
Characteristics of phase change materials: Phase change materials have a constant temperature during the phase change process and can absorb or release a large amount of latent heat. For example, paraffin is a common phase change material with a phase change temperature of about 50°C and a latent heat of 200 J/g, which means that during the phase change process, each gram of paraffin can absorb or release 200 J of heat. When the battery temperature rises, the phase change material absorbs heat and undergoes a phase change, thereby reducing the battery temperature; when the battery temperature drops, the phase change material releases heat, causing the battery temperature to rise, thereby maintaining the battery within a suitable operating temperature range.
Application of phase change materials: Phase change materials can be applied to the temperature management of electric scooter batteries in a variety of ways. A common method is to encapsulate the phase change material in the battery casing so that it is in direct contact with the battery. For example, a study encapsulated paraffin in the battery casing, and the experimental results showed that in a high temperature environment, the temperature rise rate of the battery was significantly slowed down, and the maximum temperature was reduced by about 10°C; in a low temperature environment, the temperature drop rate of the battery was also slowed down, and the minimum temperature was increased by about 5°C. Another method is to mix the phase change material with the battery casing material to make a composite material with phase change function. This method can make the phase change material evenly distributed in the battery casing and improve the thermal management performance of the battery casing. For example, some studies have mixed paraffin wax with polyethylene to make composite materials for the manufacture of battery shells. Experimental results show that the temperature variation of batteries with such composite shells in both high and low temperature environments is about 8°C smaller than that of batteries with ordinary shells.

2. Battery materials and chemical properties

2.1 Low temperature adaptability materials
The performance of electric scooter batteries will drop significantly in low temperature environments. The main reason is that the chemical reaction rate inside the battery slows down and the conductivity of the electrolyte deteriorates, resulting in a decrease in the output power and capacity of the battery. In order to improve the adaptability of batteries at low temperatures, researchers and manufacturers are developing and applying a variety of low temperature adaptability materials.
Electrolyte materials: Traditional electrolytes tend to solidify or become viscous at low temperatures, resulting in obstructed ion transport. New low-temperature electrolyte materials, such as organic electrolytes containing special additives, can maintain good fluidity at lower temperatures and improve ion conductivity. For example, the electrolyte with the addition of ethylene glycol dimethyl ether (G2) has an ion conductivity at -20°C that is 30% higher than that of ordinary electrolytes, significantly improving the low temperature performance of the battery.
Electrode materials: The activity of electrode materials is also affected at low temperatures. By adding nano-scale conductive additives such as carbon nanotubes or graphene to the electrode material, the conductivity of the electrode and the utilization rate of the active material can be improved. Studies have shown that the discharge capacity of lithium-ion battery electrodes with 5% graphene added at -10°C is 40% higher than that of electrodes without graphene, which effectively alleviates the impact of low temperature on battery capacity.
Diaphragm material: The diaphragm tends to become brittle at low temperatures, affecting the internal structure and performance of the battery. New low-temperature diaphragm materials, such as polyethylene/polypropylene composite diaphragms, have good flexibility and porosity and can maintain stable ion transmission channels at low temperatures. Experiments show that the internal resistance of batteries using this composite diaphragm at -30°C is only 20% higher than that at room temperature, while the internal resistance of batteries with ordinary diaphragms increases by 50%.

2.2 High-temperature stability materials
In high-temperature environments, the chemical reactions inside the battery are accelerated, which may cause the battery to overheat, expand, or even catch fire. Therefore, improving the stability of the battery at high temperatures is the key to preventing battery damage.
Thermally stable electrolyte: The decomposition and volatilization of electrolytes at high temperatures are one of the main reasons for the decline in battery performance. Developing electrolyte materials with high thermal stability, such as using solid electrolytes or high-boiling-point organic electrolytes, can effectively reduce the volatilization and decomposition of electrolytes. For example, the thermal stability of solid electrolytes at 80°C is 50% higher than that of liquid electrolytes, significantly reducing the self-discharge rate of batteries at high temperatures.
High-temperature resistant electrode materials: Electrode materials are prone to structural changes and active material shedding at high temperatures. The thermal stability of electrodes can be improved by adding high-temperature stabilizers, such as alumina or titanium dioxide, to electrode materials. Studies have shown that the cycle stability of lithium-ion battery electrodes with 3% alumina added at 60°C is 35% higher than that of electrodes without addition, effectively extending the service life of the battery.
Insulation materials: Using insulation materials in the battery casing can effectively reduce the impact of external high temperatures on the inside of the battery. Common insulation materials include aerogels, foam ceramics, etc. For example, in a 70°C environment, the internal temperature of a battery using an aerogel insulation layer is only 15°C lower than the external temperature, while the internal temperature of a battery without an insulation layer is only 5°C lower than the external temperature.

3. Battery Management System (BMS) Function

3.1 Temperature Monitoring and Early Warning
The Battery Management System (BMS) is one of the key technologies to prevent the battery of electric scooters from being damaged at extreme temperatures. BMS monitors the temperature of the battery in real time to ensure that the battery is always within a safe operating temperature range.
Precise layout of temperature sensors: BMS arranges multiple high-precision temperature sensors inside the battery pack, which can collect temperature data of the battery in real time. For example, the BMS system of a certain electric scooter is equipped with a temperature sensor near each battery cell, and its measurement accuracy can reach ±0.5℃. This high-density sensor layout can accurately monitor the temperature changes of the battery at different locations and detect local overheating or overcooling in time.
Intelligent early warning mechanism: The BMS system conducts intelligent analysis and judgment based on the collected temperature data and the preset safe temperature range. When the battery temperature approaches or exceeds the safety threshold, the BMS will immediately issue a warning signal. For example, when the battery temperature exceeds 45℃ or is lower than -20℃, the BMS will use sound and light alarms or display warning information on the display screen of the electric scooter to remind the user to take corresponding measures. This early warning mechanism can effectively prevent the battery from running for a long time at extreme temperatures, thereby reducing the risk of battery damage.
Data recording and analysis: BMS not only monitors and warns in real time, but also records the temperature change data of the battery. By analyzing these data, users can understand the temperature performance of the battery under different environmental conditions, thereby optimizing the battery use and maintenance strategy. For example, a research institute found through analyzing the data recorded by BMS that in a high temperature environment, the temperature rise rate of the battery is closely related to the riding speed and load weight. This finding provides an important reference for the use of electric scooters.

3.2 Charge and discharge control strategy
The charge and discharge control strategy of BMS is an important means to prevent battery damage at extreme temperatures. Through reasonable charge and discharge control, the service life of the battery can be effectively extended and its performance can be improved.
Temperature-dependent charging strategy: BMS adjusts the charging current and voltage according to the real-time temperature of the battery. In a low temperature environment, the battery's charging acceptance capacity decreases, and the BMS will reduce the charging current to prevent the battery from overheating and overcharging. For example, at -10℃, the BMS reduces the charging current to 50% of the rated current and adjusts the upper limit of the charging voltage to 3.8V. This temperature-dependent charging strategy can effectively protect the battery's charging safety at low temperatures. In a high temperature environment, the BMS will limit the upper limit of the charging current and voltage to avoid excessive heat generation inside the battery. For example, at 40°C, the BMS limits the charging current to 80% of the rated current and adjusts the upper limit of the charging voltage to 4.1V, thereby reducing the risk of thermal runaway of the battery at high temperatures.
Intelligent discharge control: The BMS will also perform intelligent control according to the battery temperature during the discharge process. When the battery temperature is too high, the BMS will reduce the discharge current to reduce the heat generation inside the battery. For example, when the battery temperature exceeds 50°C, the BMS will reduce the discharge current to 60% of the rated current and limit the maximum speed of the electric scooter. This intelligent discharge control not only protects the battery, but also ensures the safe operation of the electric scooter. In a low temperature environment, the BMS will reasonably adjust the discharge current according to the battery temperature and remaining power to ensure the battery's output power and range. For example, at -15°C, the BMS will dynamically adjust the discharge current according to the remaining power of the battery to ensure that the battery can still work normally at low temperatures.
Balanced charging and discharging: BMS also has a battery balancing function, which ensures that the voltage and capacity of each battery cell in the battery pack remain consistent through balanced charging and discharging. This balancing control can effectively avoid battery damage caused by overcharging or over-discharging of individual battery cells. For example, the BMS system of a certain electric scooter performs balanced charging during each charging process to control the voltage difference of the battery pack within 0.05V. This balancing control not only improves the overall performance of the battery pack, but also extends the service life of the battery.

4. Usage and Maintenance Recommendations

4.1 Suitable Storage Conditions
During the storage process of electric scooter batteries, suitable environmental conditions have an important impact on their performance and life.
Temperature control: Extreme temperatures will accelerate the rate of chemical reactions inside the battery, resulting in a decrease in battery performance and a shortened life. Studies have shown that when the battery storage temperature exceeds 35°C, its self-discharge rate will increase by 20%, and in an environment below -10°C, the battery's electrolyte may freeze, affecting its internal structure. Therefore, it is recommended to store electric scooter batteries in an environment of 10°C to 25°C, which is the ideal temperature range for the battery to maintain optimal performance.
Humidity management: High humidity environments can easily cause corrosion of the battery shell and internal moisture, affecting the insulation performance and safety of the battery. Experiments have shown that when the relative humidity exceeds 80%, the insulation resistance of the battery will decrease by 30%. It is recommended to store the battery in a dry environment with a relative humidity of less than 60% to prevent the battery from getting damp.
State of charge: When storing batteries for a long time, its state of charge is also critical. If the battery is stored for a long time after being fully discharged, it may cause the battery to enter a deep discharge state, making it impossible to charge it again. Long-term storage at full charge will accelerate battery aging. Studies have shown that when the battery is stored at 50% of its charge, its capacity retention rate is the highest, reaching 90%. Therefore, it is recommended to charge the battery of the electric scooter to about 50% before storing it.

4.2 Charging environment optimization
The charging environment also has a significant impact on the performance and life of the electric scooter battery.
Suitable temperature: During the charging process, the battery will generate heat. If the ambient temperature is too high, the battery temperature will rise rapidly, increasing the risk of thermal runaway. Experiments show that when the charging environment temperature exceeds 40℃, the battery temperature rises 50% faster. Therefore, it is recommended to charge the electric scooter in an environment of 15℃ to 30℃ to ensure that the battery temperature is stable during the charging process.
Avoid direct sunlight: Direct sunlight will increase the surface temperature of the battery, affecting the charging efficiency and life of the battery. Studies have found that the surface temperature of the battery under direct sunlight is 15℃ higher than that in the shade. It is recommended to charge the electric scooter in a cool place and avoid direct sunlight.
Good ventilation: Good ventilation conditions can effectively dissipate the heat generated by the battery during charging and reduce the battery temperature. Experiments show that when charging in a well-ventilated environment, the temperature of the battery is 10℃ lower than that in a poorly ventilated environment. Therefore, it is recommended to choose a well-ventilated place to charge the electric scooter to improve charging safety and battery life.

5. Summary
Through the above research, we can fully understand how to prevent the electric scooter battery from being damaged at extreme temperatures. The following is a summary of various aspects:

5.1 Thermal Management System Design
The thermal management system is one of the key technologies to prevent the electric scooter battery from being damaged at extreme temperatures. Heat dissipation design and heating design play an important role in different temperature environments. Heat dissipation methods include natural heat dissipation, forced air cooling and liquid cooling. Among them, the liquid cooling system performs well in high temperature environments, and the temperature control accuracy can reach ±5℃. The heating design increases the battery temperature through electric heating or chemical heating. The electric heating system can raise the battery temperature to above 0℃ within 15 minutes in a -20℃ environment. In addition, the application of phase change materials also provides effective support for battery temperature management. For example, phase change materials such as paraffin can reduce the battery temperature by about 10°C in high temperature environments and increase the temperature by about 5°C in low temperature environments.

5.2 Battery Materials and Chemical Properties
The improvement of battery materials is crucial to improving their performance at extreme temperatures. In terms of low-temperature adaptability materials, new electrolytes such as electrolytes with added ethylene glycol dimethyl ether can increase ion conductivity by 30% at -20°C; adding graphene to electrode materials can increase discharge capacity by 40% at -10°C; and diaphragm materials such as polyethylene/polypropylene composite diaphragms only increase internal resistance by 20% at -30°C. In terms of high-temperature stability materials, solid electrolytes have a 50% increase in thermal stability at 80°C; electrode materials with added alumina have a 35% increase in cycle stability at 60°C; and thermal insulation materials such as aerogel can make the internal temperature of the battery 15°C lower than the external temperature.

5.3 Battery Management System (BMS) Function
BMS plays an important role in preventing battery damage due to extreme temperatures. In terms of temperature monitoring and early warning, the high-precision temperature sensor layout can achieve a measurement accuracy of ±0.5℃. When the temperature exceeds the safety threshold, the BMS will issue an early warning signal. In terms of charge and discharge control strategy, the BMS adjusts the charging current and voltage according to the temperature, reduces the charging current at low temperatures, and limits the current and voltage upper limits at high temperatures. The intelligent discharge control adjusts the discharge current according to the temperature to ensure the safe operation of the battery.

5.4 Usage and maintenance recommendations
Usage and maintenance recommendations are also important for extending battery life and improving performance. In terms of suitable storage conditions, it is recommended to store the battery in an environment with a temperature of 10℃ to 25℃ and a relative humidity of less than 60%, and charge it to about 50%. In terms of charging environment optimization, it is recommended to charge in an environment with a temperature of 15℃ to 30℃, good ventilation and avoiding direct sunlight.

In summary, through the design of thermal management systems, battery material improvements, BMS function optimization, and reasonable use and maintenance, electric scooter batteries can be effectively prevented from being damaged at extreme temperatures, extending battery life and improving their performance.