The safe use of Li-ion batteries under different environmental conditions is crucial. in all environments. Temperature has the greatest impact on the charging and discharging capabilities of Li-ion batteries. The electrochemical reactions at the electrode/electrolyte interface depend on the ambient temperature. The electrode/electrolyte interface is considered the blood of Li-ion batteries.
If the temperature drops, so does the response of the electrodes: If the voltage of a Li-ion battery remains constant, the discharge current drops. Then the power output of the lithium-ion battery will also drop. The opposite is true if the temperature rises. That is, the output power of the lithium-ion battery will increase. The temperature also affects the transport speed of the electrolyte, which is accelerated when the temperature rises and slowed down when the temperature falls: the charging and discharging functions of lithium-ion batteries are also affected. But the temperature is too high. It will destroy the chemical balance in the lithium-ion battery. If a single 20Ah lithium-ion battery is taken as an example, the usual environmental test is carried out:
- When the lithium-ion battery is fully charged, store it in a low-temperature test box with an environment of (-202)°C for 20 hours. Under (-202)°C ambient conditions, discharge with 1IVA current. Until the discharge stop voltage is 2.OV, the capacity of the lithium-ion battery should not be lower than 70% of the limit value. The measured battery capacity is 20Ah. Also read:48v lithium golf cart battery
- In a test chamber with an ambient temperature of (20_+5) °C at normal temperature. Discharge the lithium-ion battery with a current of 1IVA until the discharge stop voltage is 2.0V. At this time, this group of batteries is detected. Its capacity value should not be lower than the limit value or exceed the capacity value. The capacity test value is 21Ah, which is 105% of the limit value, indicating that the lithium-ion battery is within the normal range at (20_+5) °C normal temperature.
- When the lithium-ion battery is fully charged, store it in a high-temperature test box with an environment of (552)°C for 5 hours, and then discharge it at a current of 1IVA at (552)°C until the discharge stop voltage is 2.0V .Its capacity should not be lower than 95% of the limit value. The actual measured capacity value is 20Ah, which is the limit value. It is stated that the capacity value does not change at a high temperature of 55°C.
Although it is theoretically stated that the environment has an impact on lithium-ion batteries. But the test shows that the lithium-ion battery is even under the condition of changing temperature. The capacity value has not changed very much. Therefore, changes in ambient temperature do not have much impact on lithium-ion batteries.