Pacific Automotive Network's ternary lithium battery cannot be used at minus 10 degrees Celsius, and lithium-ion batteries cannot be exposed to too low a temperature. At too low temperatures, lithium is deposited in the battery, causing an internal short circuit. Simply put, in a low temperature environment, it is not that the lithium battery is really discharged, but that it is powered but cannot be released normally. The capacity of ordinary lithium batteries will be reduced by 20% at zero degrees Celsius, and when it reaches minus 10 degrees Celsius, the capacity may only be about half.
Why can't lithium-ion batteries be charged in low temperature environments? Lithium-ion batteries cannot be exposed to extremely low temperatures. At too low temperatures, lithium is deposited in the battery, causingdue to an internal short circuit. Simply put, in a low temperature environment, it is not that the lithium battery is really discharged, but that it is powered but cannot be released normally. The capacity of ordinary lithium batteries will be reduced by 20% at zero degrees Celsius, and when it reaches minus 10 degrees Celsius, the capacity may only be about half.
Ternary low temperature rechargeable battery, the lithium iron phosphate system is charged at -20°C to 0.5°C, and the charge and discharge cycle is more than 300 cycles, it is charged at -40°C to 0.5°C; 0.2C, and the charge and discharge cycle is more than 300 cycles.
Ternary low temperature discharge battery, lithium iron phosphate system -40°C high rate continuous discharge 5C, capacity retention rate above 80°C; .
Why can't lithium-ion batteries be charged in environmentss at low temperature?
Most materials in lithium-ion batteries, such as separators and electrolytes, are organic materials with low melting and boiling points. If the temperature is too high, some negative chemical reactions will occur inside the battery, which will seriously affect them. battery life and even security performance.
Under low temperature conditions, the conductivity of key materials of lithium-ion batteries, such as positive electrode, negative electrode and electrolyte, decreases, leading to a decrease in conductive performance and seriously affecting the lifespan. of the lithium battery.
For lithium batteries, there is currently no clear theory in the industry to support the inevitable relationship between internal resistance, discharge platform, life, capacity, etc. under various pertemperature forms. Calculation formulas and relevant mathematical models. are still under study. Generally speaking, lithium batteries are not sensitive to temperatures between 0 and 40°C. However, once the temperature exceeds this range, the lifespan and capacity will be compromised.
We have carried out many experiments and found that the low temperature performance of lithium batteries of different materials is also different. The most popular lithium iron phosphate now has the worst low temperature performance. Our products have the maximum. discharge capacity at -10°C. The 89% should be relatively high in the industry; the discharge capacity can reach 95% at 55°C, and the attenuation at relatively low temperatures is relatively small. This is still a product sent for inspection. As you know, the quality is much higher than the pnormal products on the assembly line.
Low temperature protection means that when the temperature is too low, the lithium metal in the lithium-ion battery will settle and no longer react chemically with the substance, resulting in an internal short circuit in the battery. battery.
Since the working principle of lithium-ion batteries is that the internal electrolyte changes through chemical reactions, a potential difference occurs between the positive and negative electrodes, thereby generating current. in lowThe electrolyte moves very slowly in a hot environment, which affects the transfer activity of lithium ions between the positive and negative electrodes, resulting in a decrease in the charging and discharging performance of the battery.
Some people report that lithium-ion batteries cannot be charged in winter. Some people with bat management systemsLithium ries are due to product protection, and others cannot be charged due to quality problems.
The duration of use of lithium batteries in winter is necessarily shorter than in summer. I would like to remind you that it is better not to charge lithium batteries in winter. Due to the low temperature, the lithium ions nestled on the negative electrode will produce ion crystals and directly pierce the separator. Under normal circumstances, it will cause micro-short circuit, affect service life and performance, and may explode in severe cases.
The impact of lithium batteries in low temperature environments Low temperatures impact the positive and negative electrodes, electrolytes and adhesives of lithium iron phosphate batteries.
(Images/Text/Photos: Pacific Automotive Network Calling the Beast Q&A)