Introduction:
Lithium batteries have become an integral part of our daily lives, powering everything from smartphones and laptops to electric vehicles and energy storage systems. Lithium batteries are widely used, but there have been cases of fires and explosions, which, although rare, have raised concerns about their safety. Understanding the factors that may lead to such incidents is critical to ensuring the safe and reliable use of lithium batteries.
Lithium battery explosions are a serious safety issue, and the causes of their occurrence are complex and varied, mainly including internal and external factors.
Internal factors
Internal short circuit
Insufficient negative electrode capacity: When the negative electrode capacity of the positive electrode of a lithium battery is insufficient, the lithium atoms generated during charging cannot be inserted into the interlayer structure of the negative electrode graphite, and will precipitate on the surface of the negative electrode to form crystals. The long-term accumulation of these crystals may cause a short circuit, the battery cell discharges rapidly, generates a lot of heat, burns the diaphragm, and then causes an explosion.
Electrode water absorption and electrolyte reaction: After the electrode absorbs water, it may react with the electrolyte to produce air bulges, which may further cause internal short circuits.
Electrolyte problems: The quality and performance of the electrolyte itself, as well as the amount of liquid injected during injection that does not meet the process requirements, may affect the safety of the battery.
Impurities in the production process: Impurities, dust, etc. that may exist during the battery production process may also cause micro-short circuits.
Thermal runaway
When thermal runaway occurs inside a lithium battery, an exothermic chemical reaction will occur between the internal materials of the battery, and flammable gases such as hydrogen, carbon monoxide, and methane will be produced. These reactions will lead to new side reactions, forming a vicious cycle, causing the temperature and pressure inside the battery to rise sharply, and eventually leading to an explosion.
Long-term overcharging of the battery cell
Under long-term charging conditions, overcharging and overcurrent may also lead to high temperature and high pressure, which in turn may cause safety hazards.
External factors
External short circuit
Although external short circuits rarely directly cause battery thermal runaway, long-term external short circuits may cause weak connection points in the circuit to burn, which in turn may cause more serious safety problems.
External high temperature
Under high temperature environments, the electrolyte solvent of lithium batteries evaporates faster, the electrode materials expand, and the internal resistance increases, which may cause leakage, short circuits, etc., causing explosions or fires.
Mechanical vibration or damage
When lithium batteries are subjected to strong mechanical vibration or damage during transportation, use or maintenance, the diaphragm or electrolyte of the battery may be damaged, resulting in direct contact between metal lithium and electrolyte, triggering an exothermic reaction, and ultimately leading to explosion or fire.
Charging problem
Overcharge: The protection circuit is out of control or the detection cabinet is out of control, causing the charging voltage to be greater than the rated voltage of the battery, resulting in electrolyte decomposition, violent reactions inside the battery, and rapid rise in the internal pressure of the battery, which can cause explosion.
Overcurrent: Excessive charging current may cause lithium ions to not have time to embed into the pole piece, and lithium metal is formed on the surface of the pole piece, penetrating the diaphragm, causing a direct short circuit between the positive and negative poles and explosion.
Conclusion
The causes of lithium battery explosions involve internal short circuits, thermal runaway, long-term overcharging of the battery cell, external short circuits, external high temperatures, mechanical vibration or damage, charging problems, and other aspects. Therefore, when using and maintaining lithium batteries, it is necessary to strictly abide by relevant safety regulations to ensure the safety and stability of the battery. At the same time, strengthening safety supervision and preventive measures are also important means to prevent lithium battery explosions.
Heltec Energy is your trusted partner in battery pack manufacturing. With our relentless focus on research and development, coupled with our comprehensive range of battery accessories, we offer one-stop solutions to meet the evolving needs of the industry. Our commitment to excellence, tailored solutions, and strong customer partnerships make us the go-to choice for battery pack manufacturers and suppliers worldwide.
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Post time: Jul-24-2024