Asthecoreofmodernenergystoragetechnology,lithiumbatteriesarewidelyusedinelectricvehicles,portableequipmentandenergystoragesystems. However,many users will encounter the problem of lithium battery capacity suddenly diving during use,resulting in a sharp decrease in the battery life or performance of the device.Thisarticlewillanalyzeindetail the commoncausesofabnormalattenuationoflithiumbatterycapacityandsharepracticalsolutions. Common reasons for lithium battery capacity diving:
1. Aging of materials and shedding of active substances The capacity decay of a lithium battery is closely related to the stability of its internal materials. After long-term use, the active materials of the positive electrode (such as lithium iron phosphate) and the negative electrode (graphite) may gradually fall off due to repeated charging and discharging, resulting in a decrease in the efficiency of the electrochemical reaction. In addition, by-products from electrolyte decomposition can corrode the electrode material, further accelerating capacity decay. solution： (1) Choose lithium batteries with high cycle life (such as lithium iron phosphate), which have better thermal stability and structural strength than ternary lithium batteries. (2) Avoid over-discharge (SOC is recommended to be kept at 20%-80%). 2. Manufacturingdefectsordefectsinworkmanship Some lithium batteries may have problems such as impurity pollution,uneven coating of electrode pieces or poor welding in the production process,which may lead to increased local internal resistance or increased risk of short circuit.Thistypeofdefectdirectlyleadstoabnormalvolumeattenuation. solution： (1) Sourcing ISO 9001-certified lithium battery brands (e.g., CATL, BYD) to ensure compliant production processes. (2) Strict testing of battery consistency (e.g. capacity deviation ≤5%) at the time of receipt. 3. Extreme temperature environmental impacts Lithium batteries are temperature sensitive, and long-term exposure to high temperatures (>60°C) or low temperatures (<-20°C) will lead to deterioration of electrolyte performance. For example, high temperatures accelerate electrolyte breakdown, while low temperatures reduce the rate of lithium-ion migration, both of which can lead to capacity dives. solution： (1) In high-temperature scenarios, configure a heat dissipation system (e.g., liquid/air-cooled) for the lithium battery. (2) Preheat the battery before use in a low-temperature environment, or choose a low-temperature resistant model (such as an IP67-rated battery).
4. Overcharge and overdischarge and improper charging management Overcharging can lead to the collapse of the cathode material structure, while overdischarge may cause lithium precipitation at the negative electrode, both of which can seriously damage the health of the battery. In addition, using a mismatched charger (e.g., excessive current) can accelerate battery aging. solution： (1) The BMS (Battery Management System) is used to monitor voltage, current, and temperature in real time. (2) Use the original matching charger to avoid impulse fast charging.
5. Mechanical damage or seal failure Physical impact, punctures, or poor housing seals can cause electrolyte leaks, which can cause battery capacity to plummet. This type of problem is common with lithium batteries that are not properly packaged during transportation. solution： (1) Choose shock-resistant packaging (e.g. ISTA 3A certified material) for shipping. (2) Regularly check the integrity of the battery case to avoid secondary damage.
