The main risk of lithium-ion batteries is related to the amount of energy they contain. In extreme cases, caused by improper use or external factors, short circuits and even combustion may occur. This occurs by releasing oxygen when thermal runaway occurs, which means that the fire generated induces a chain reaction. This is the case in smartphones, electric vehicles and even large-scale energy storage plants. In this environment, personal electrical protection for workers in the automotive industry is therefore essential.

Battery types for electric vehicles

Today, the evolution of the automotive industry itself is leading the way when it comes to powering its vehicles. What were originally lead-acid batteries are now also used in the market for nickel/cadmium (NiCd) and, for hybrids, nickel-metal hydride (NiMH) batteries.

However, lithium-ion/lithium-ion (LiCoO₂) batteries are worth highlighting, as they are the most widely used batteries for electrics. It is a system with twice the energy density of NiCd and one third the size. Their life cycle is between 400 and 1,200 charges and discharges, and they have a density of 100-250 wh/kg with no need for maintenance.

• Advantages: Light weight, high efficiency and no memory effect.
• Disadvantages: Their fragility and the fact that they require a safety circuit and careful storage.

How to protect hands from thermal runaway in lithium-ion batteries

Generally, these accumulators undergo a process of deterioration and wear throughout their life cycle due to both physical and chemical factors. Its operation is based on a reversible reaction between a negative electrode (such as graphite) and a positive electrode (such as cobalt dioxide or magnesium dioxide).

When both electrodes are immersed in a liquid electrolyte, which is usually a solution of lithium hexafluorophosphate salts (LiPF₆) with ethylene carbonate and propylene or tetrahydrofuran, a reaction occurs that releases energy in the form of electricity. Therefore, in the particular case of assembly, the correct protection when handling these batteries is the use of gloves for electric vehicle assembly.

Thermal runaway and temperature sensitivity

Due to their greater sensitivity to temperature compared to conventional batteries, electric vehicle batteries can experience irreversible thermal episodes due to various factors. Such is the case of internal or external short circuits, overloads, external heating, fire or mechanical abuse.

These incidents can trigger thermal runaway caused by the exothermic reactions of the battery, ranging from rapid emission of dense smoke to flames, continuous combustion or even explosions. Therefore, only insulating gloves for electric vehicle workers can prevent these thermal hazards.

Toxic emissions in battery combustion: gloves for electric vehicle assembly

Another significant risk is leakage of the liquid electrolyte. LiPF₆, being a flammable, hygroscopic and corrosive compound in liquid form, reacts very easily with mucous tissues and causes burns to the skin, eyes, gastrointestinal and respiratory tract.

Similarly, if a lithium-ion battery burns, it releases toxic substances such as hydrofluoric acid, gaseous hydrogen fluoride or phosphorus pentafluoride. In fact, the amount of toxics formed during battery combustion is enormous. To defend against them, antistatic gloves for electric car assemblers are especially recommended.

Personal electrical protection for automotive industry workers

Although lithium-ion batteries are generally safe during normal operation, safety must be a priority when operating lithium-ion batteries. Area managers, whatever the process or sub-process, must be aware of the potential risks involved. When working with lithium-ion batteries, the choice of the right personal protective equipment for electric vehicle assembly makes all the difference. It should not be forgotten that this is the last line of defense against accidents and unforeseen events such as thermal leaks or other hazards.

Do you want to avoid the chemical hazards of lithium-ion batteries?

Safety managers play an essential role in providing and ensuring the effective use of PPE. For example, when implementing PPE for automotive electrical installers, even in seemingly routine situations. Commitment to safety ensures a safe environment for all. Precisely for this reason, AnsellGUARDIAN® Chemical simplifies the process of selecting personal protective equipment for the manufacture of electric vehicles.

By using our digital tools, you can easily access Ansell's extensive penetration and degradation database. What's more, you can perform comprehensive product searches based on your application requirements or download Ansell's complete test data on a product. All at the click of a button.