Lithium-ion batteries are a disruptive technology that has significantly altered almost every industry sector. As a result, they have become the industry standard for all rechargeable storage devices.
Today, they are a crucial, if not the central, component in the next generation of power systems and green or renewable technologies. However, since batteries are a complex technology comprising many interrelated scientific phenomena, their utilization and deployment must be built upon a basis of safety.
Lithium-ion battery fires and accidents are rising and present risks that create challenges for use, storage, and handling. Most fire hazards are associated with the high energy densities coupled with the flammable organic electrolyte.
Studies show that physical damage, electrical abuse such as short circuits and overcharging, and elevated temperature exposure can cause a thermal runaway which refers to rapid self-heating from an exothermic chemical reaction. This can be caused by manufacturer’s defects such as imperfections and/or contaminants in the manufacturing process.
Several rules and requirements have evolved to cover a full spectrum of risk today. Still, the complexity of safety aspects means that additional learning and understanding provide an opportunity to improve safety and efficiency. This post will cover the best practices to store, recharge, handle and dispose of Lithium-ion batteries to avoid fire and safety hazards.
Storage
- Remove all batteries from the device for long-term storage.
- If possible, store batteries in metal storage cabinets. Avoid bulk storage of batteries.
- Charge the stored batteries to approximately 50% of capacity once every six months.
- Store the batteries at temperatures between 41°F and 68°F (5°C and 20°C)
- Store batteries away from combustible materials. Store one-time use batteries separately.
- Visually inspect battery storage at least weekly. You must separate new and depleted cells (or keep a log).
- Don’t use the charger as a storage location.
- Keep batteries away from contacting conductive materials, water, seawater, strong oxidizers, and strong acids.
- Do not place batteries in direct sunlight, on hot surfaces, or in hot locations.
Charging
- Use specified chargers or charging methods designed to safely charge cells or battery packs at the specified parameters.
- Never charge primary batteries (disposable lithium or alkaline).
- Promptly remove cells and pack from chargers after charging is complete.
- Do not parallel charge batteries of varying ages and charge statuses because chargers cannot monitor the current of individual cells. The initial voltage balancing can lead to high amperage, battery damage, and heat generation. Check the voltage before parallel charging. All batteries must be within 0.5 Volts of each other.
- Disconnect batteries immediately if they emit an unusual smell, develop heat, change shape/geometry, or behave abnormally during operation or charging.
- Do not overcharge (greater than 4.2V for most batteries) or over-discharge (below 3V) batteries.
Handling
- Handle the batteries and battery-powered devices cautiously to not damage to the battery casing or connections.
- Inspect batteries for signs of damage before every use. Never use and promptly dispose of damaged or puffy batteries.
- Allow time for cooling before charging a battery that is still warm from usage or charging.
- Dispose of all cells that are damaged or can no longer hold a substantial charge.
Emergency measures
You must follow these steps in case of all battery malfunctions (e.g., swelling, heating, or irregular odors).
- If batteries show thermal runaway failure, be very cautious because the gases may be flammable and toxic, and failure modes can be hazardous.
- Use personal protective equipment, such as goggles/safety glasses, gloves, etc.
- Remove the battery from the device/ equipment (if possible).
- Place the battery away from combustibles.
- If a battery fire occurs, use a CO2 or dry chemical fire extinguisher.
