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Lithium-Ion Battery Storage

Battery technology has been with us for well over a century and continues to evolve. Lead-acid batteries came on the scene in the early 20th century primarily as a result of the automotive industry. With few modifications, this exact technology exists today and is still starting automobiles and serving as uninterruptible power supplies for business and industry.

In the 1970s, the need for reliable, rechargeable power sources for consumer products and medical devices drove the widespread adoption of nickel-cadmium (NiCd) batteries. These were superseded in the 1980s by nickel-metal hydride (NiMH) batteries which provided a less toxic alternative to NiCd batteries along with a higher energy density. Aside from consumer products, they were particularly popular in early hybrid electric vehicles.

Battery technology took a quantum leap forward in the 1990s when lithium-ion batteries entered the market. The new technology significantly improved safety, energy density, and longevity, revolutionizing portable electronics such as mobile phones and laptops.

Lithium-ion (li ion) research and development continued into the 21st century, and the technology has evolved to a point where virtually all consumer products are powered by li ion batteries. They now power electric vehicles and are used in battery energy storage systems to store excess power produced by renewable energy sources. Their adoption is so widespread that it is estimated that 90 percent of all large-scale battery energy storage facilities use li ion battery systems.

Lithium-Ion Batteries—With Popularity, Risk Follows

Li ion batteries are so popular mainly because of their high energy density. This means they can squeeze a substantial amount of stored energy into a relatively small and light package. They also recharge faster than other batteries and have a long service life. And with the ongoing concern over global warming and the push for greener energy, li ion batteries are seen as having a central role in meeting climate-change targets.

Whenever a substantial amount of energy is confined within a limited space, risks inevitably arise. The influx of lithium-ion batteries into society has heightened these risks, leading to a surge in fires and explosions across various levels of lithium-ion battery usage. A simple internet search yields countless incidents, spanning from exploding cell phones to electric car fires and even large-scale conflagrations involving commercial battery energy storage facilities.

Li-ion battery and drillLi-ion battery and drill

In 2018, the https://www.osha.gov/sites/default/files/publications/shib011819.pdf reported over 25,000 incidents of overheating or fire involving more than 400 types of lithium battery-powered consumer products over a five-year period. In addition to this troubling statistic is the death and injury toll. In 2023, in New York City alone, the FDNY reported 150 injuries and 18 deaths from 267 fires started by li ion batteries

Lithium Ion batteries can fail with virtually no warning, complicating the risk factor, and the resulting fires produce toxic and flammable vapors and are notoriously difficult to extinguish. In many instances—such as with electric vehicles (EVs)—the populace is at the mercy of the li ion battery. But for rechargeable batteries—such as those used to power tools and other consumer products—new advances by Justrite in li ion battery charging and storage are setting the stage to disrupt the free reign of destruction caused by li ion fires and explosions.

Understanding Lithium-Ion Batteries

To fully understand the risk posed by li ion batteries, it is important to first understand how they work. Their beauty lies in their simplicity. Li ion batteries contain a positive cathode and a negative anode. During discharge, lithium ions move from the negative anode to the positive anode and vice versa when charging. The internal components are contained in a housing filled with a liquid ion-conducting electrolyte. Because the electrolyte is a flammable solvent, this is where the fire and explosion risk originate.

A single cathode/anode arrangement is called a “cell.” Cellular phones generally have a single cell, while rechargeable tools may have up to 20. EVs may have hundreds of cells; commercial battery energy storage systems may have thousands. Each cell poses a risk, which must be considered.

How Lithium-Ion Batteries Fail

Despite lithium-ion battery fires frequently grabbing headlines and dominating online discussions, the technology is largely considered safe. However, when these batteries do fail, they often do so in a spectacular manner. Compounded by their difficulty to extinguish, these fire incidents often attract widespread attention in both traditional news outlets and social media platforms.
To better understand the risk, it is important to understand what causes li ion batteries to fail, how they fail, when they fail, and what often occurs after they fail.

Bulging li-ion batteryBulging li-ion battery

There are a few causes for the failure of li ion batteries:

  • Manufacturing defects 
  • Design flaws
  • Poor quality products (unregulated imports)??
  • Overcharging
  • Physical damage
  • Exposure to temperature extremes

Of these causes, the most common appear to be manufacturing defects and design flaws. With so many li ion-powered products on the market, not all are manufactured according to the strict tolerances required to operate the battery safely; this makes them far more susceptible to failure.

While a li ion battery can fail at any time, they tend to fail the most frequently during charging. If there are manufacturing defects (e.g., tiny metal particles in the battery case), this can lead to short circuits. Also, if there are design flaws in protection circuits to prevent overcharging, this can also lead to battery failure. 

Aside from manufacturing issues, charging creates voltage stress on the battery’s electrodes causing lithium metal plating on the anode which reduces the battery’s overall capacity and can cause an internal short circuit. If batteries are charged too quickly, they can overheat, also resulting in failure. 

Regardless of the precipitating event that induces battery failure – when it fails, it will follow the same cycle of events. In some instances, the failure may transpire quickly or, it may take hours or even days. Not all battery failures make it through the entire failure cycle, but many do.

After the battery has been compromised by one of the causes listed above, it enters the first stage of failure. The battery’s internal temperature and pressure will increase due to the accumulation of flammable gases caused by the vaporization of the electrolyte solution.

Continued failure of the battery leads to a short circuit of the cathode and anode. Because the energy remaining in the battery rapidly flows through the short circuit, the battery’s temperature rises rapidly to over 500°F (260°C). The high temperature creates significant smoke production which escapes the battery’s container. This is often the first external indication of a problem with the battery. Since the smoke is comprised of vaporized electrolyte, it is flammable and may ignite if it contacts an ignition source. Smoke production can also signal the onset of a thermal runaway.

Thermal runaway occurs in multi-cell li ion batteries. It is a chain-reaction event where one overheated cell causes an adjacent cell to overheat and begin the failure process. The chain reaction may continue until all cells within the battery of origin are failing and can additionally extend to the other nearby batteries.

The last phase of the cycle is fire. Fire may occur soon after smoke emanates from the battery but before thermal runaway occurs. In other instances, thermal runaway may proceed for a period of time filling the battery’s enclosure with flammable vapors, thus creating an explosive environment. Either way, once a battery begins producing flammable smoke, it will almost certainly reach the fire phase and extend to nearby combustibles. 

Risks Associated with Lithium-Ion Battery Fires

As we mentioned, one of the most frightening aspects of li ion incidents is that they can occur with no warning. A battery that has been trouble-free for years can suddenly fail and create a devastating fire. And the phenomenon is becoming more frequent. In New York City, the FDNY reports that li ion battery failures are the third leading cause of fires, behind only smoking and open flames. 

When li ion batteries burn, they produce a toxic and/or flammable soup of vapors. Almost all li ion battery fires will produce carbon dioxide, carbon monoxide, hydrogen, hydrofluoric acid, some form of metal oxides, lithium hydroxide, aldehydes, and volatile organic compounds (VOCs). 

Lithium ion battery on fireLithium ion battery on fire

Depending on the cathode material, a burning battery may also produce phosphorous oxyfluoride, sulfur dioxide, cobalt oxide, nickel oxide, or manganese oxide. All of these are bad actors if they encounter people, animals, or the environment. 

But perhaps the biggest issue is the difficulty in extinguishing a li ion fire, particularly when multi-cell batteries are involved. Portable fire extinguishers have no effect, thus forcing fire departments to use considerable amounts of water for extended periods of time. At many li ion fire scenes, the firefighters’ primary goal is to contain the fire and prevent it from spreading to adjacent combustibles.

In large-scale battery energy storage installations, operators are having success with specialized fixed fire suppression systems. While these installations do experience fires, the fixed systems often represent a considerable investment and require extensive testing and maintenance. Many companies cannot afford to implement such systems. 

Thankfully, innovations by Justrite in li ion battery storage are offering consumers and businesses a fire- and explosion-resistant battery cabinet in which to safely charge their li ion batteries. The cabinet houses the batteries during charging while an integral fan keeps the compartment cool to prevent overheating. Should a battery fail, the cabinet contains the fire and various other features react to also contain the toxic and flammable products of combustion. 

Effective containment is the best strategy currently available to protect life and property from the dangers of li ion batteries. But it is up to consumers and businesses to proactively take this step; that is because—as you will see below—the regulatory requirements are currently quiet on the matter.

Justrite Lithium Ion Battery Charging Cabinet, model 231703Justrite Lithium Ion Battery Charging Cabinet, model 231703

Regulations and Standards for Lithium-Ion Battery Safety

Because of the rising number of incidents stemming from li ion batteries, the codes and standards organizations are starting to get involved. Most notably, amendments to the 2024 International Fire Code (IFC) outline very specific requirements for businesses that use li ion batteries.

Within Section 320 of the 2024 IFC are new requirements addressing:

  • Permits
  • Fire safety plans
  • Storage requirements
  • Limited indoor storage in containers
  • Indoor storage areas
  • Outdoor storage
Caution Lithium Battery signCaution Lithium Battery sign

In addition to the IFC, U.L. (Underwriters Laboratories) has numerous standards that apply to li ion batteries to ensure their safety, performance, and reliability. These standards cover various aspects of battery technology, including design, manufacturing, testing, and handling.

Pertaining to consumer-grade li ion batteries, these include:

UL 1642—Lithium Batteries: This standard applies to lithium batteries (both rechargeable and non-rechargeable). It focuses on the safety of lithium cells and batteries concerning risks of fire, explosion, and leakage. U.L. 1642 evaluates the construction, performance, and marking of the batteries.

UL 2054—Household and Commercial Batteries: UL 2054 covers safety requirements for household and commercial batteries under intended use and reasonably foreseeable misuse. It includes requirements for li ion batteries used in portable and stationary applications, addressing risks related to electrical, mechanical, and environmental performance.

OSHA (the Occupational Health and Safety Administration) has no standards specific to li ion battery storage or use. It has issued the safety bulletin Preventing Fire and/or Explosion Injury from Small and Wearable Lithium Battery Powered Devices in an effort to protect workers that wear battery-powered devices. 

The NFPA (National Fire Protection Association) has standards that apply to large-scale battery energy storage systems, specifically, at NFPA 855 Standard for the Installation of Stationary Energy Storage Systems. NFPA 855 is also mentioned in NFPA 1 Fire Code. But for consumer-grade li ion battery storage and use, like OSHA, they have issued a variety of safety bulletins

The International Electrotechnical Commission (IEC) has established the following standards:

IEC 62133: Safety requirements for portable sealed secondary cells, and for batteries made from them, for use in portable applications; this is widely adopted for consumer electronics.

IEC 62619: Safety requirements for secondary lithium cells and batteries, for use in industrial applications.

When it comes to li ion battery fires, NEMA (the National Electrical Manufacturers Association) has issued Standards Publication BS 30000-2021, Lithium-Ion Battery Fires Guidance Document. One of the few standards to specifically address the li ion battery fire issue, and specifically its suppression, NEMA recommends containment as a primary means of protection against li ion fires. Notably, this is also a strategy used successfully by the airline industry.

Beyond containment, NEMA states that fire protection for the li ion battery risk requires a significant investment in technology—i.e., gas detection equipment, fire detection devices, and advanced fire suppression systems. 

Safe Lithium Ion Battery Charging Cabinets from Justrite

No battery storage or usage is entirely devoid of risk. However, the widespread adoption of lithium-ion batteries is bringing attention to the risks associated with their storage and utilization.

Acknowledging this necessity, Justrite offers a proactive solution through our Lithium-Ion Battery Charging Safety Cabinet. Rather than leaving safety to chance, both consumers and businesses can now take proactive measures to shield themselves from the genuine hazards posed by lithium-ion batteries.