Electronic cigarettes, vaporizers, vape pens, and other electronic nicotine delivery system (ENDS) products (“e-cigs”) continue to make headlines due to malfunctions that sometimes result in combustion. These incidents often stem from overheating or other failures of the lithium-ion batteries powering these devices, and can lead to product liability claims. This client alert examines the role of lithium-ion batteries in e-cig technology, the causes of lithium-ion battery malfunctions, and technological advancements designed to address potentially dangerous malfunctions.
1. The Role of Lithium-Ion Batteries in E-Cig Technology
E-cigs release vaporized e-liquid that is inhaled by the user in a process known as “vaping.” E-cigs contain at least two basic components: a battery and an atomizer, which contains a metal coil and e-liquid. The battery heats the coil, which in turn heats the e-liquid into vapor. Lithium-ion batteries are rechargeable, and are found in a wide array of products beyond e-cigs, including electric cars, laptops and smart phones.
Lithium-ion batteries contain a positive electrode and a negative electrode divided by a separator. The separator, usually a very thin sheet of plastic, acts to keep the positive and negative electrodes separate while allowing the ions to pass through. The battery contains liquid electrolyte, and during charging, lithium ions move through the electrolyte from the positive electrode to the negative electrode. When the device is in use, the opposite occurs and lithium ions move from the negative electrode back to the positive electrode.
While lithium-ion batteries contain certain protections and safety features, the liquid electrolyte inside the battery is highly flammable. Therefore, if the separator ruptures, or the overcharge protection fails resulting in overcharging, the battery can short circuit and the flammable electrolyte can combust.
2. Causes of Lithium-Ion Battery Malfunctions in E-Cigs
While lithium-ion batteries have caused overheating or combustion in a variety of personal electronic devices, the U.S. Fire Administration has suggested that e-cigs present a unique hazard due to their shape and design.[1] Because e-cigs are often cylindrical, when a battery in an e-cig combusts, it can propel out of the device with extreme force. In addition, the fact that e-cigs are inherently used close to one’s body increases the danger if combustion does occur. Indeed, it was determined that out of 195 e-cig fire and explosion incidents between January 2009 and December 2016, more than 60 percent of the incidents occurred when the device was either in a pocket or actively in use.[2]
Lithium-ion battery failures in e-cigs can be either external or internal and caused by a variety of factors. External failures occur when a certain amount of microscopic metal particles converge on one spot, creating an electrical short and a sizable current flow between the positive and negative electrodes, leading to combustion. For instance, external failures can result from the battery coming into contact with metal, such as keys or loose change in a user’s pocket. Unlike with laptops or cell phones, many e-cig users also carry spare batteries on their person, which makes the possibility of an external failure more likely.
Internal failures can result from poor manufacturing. For instance, if the separator is manufactured poorly or is damaged, the positive and negative electrodes can come into contact, leading to an internal short-circuit and subsequent build-up of heat, triggering a thermal runaway in which the battery overheats and can burst into flames. Failures can also result from user error or reconfiguring e-cigs, which is often done to create more vapor. For example, sub-ohm vaping occurs when the resistance on the atomizer coils is less than one ohm, which increases the power output on the device. This generates a greater amount of heat within the e-cig, increases the likelihood of straining the power supply, and can create a higher likelihood of combustion.
Over-discharging can occur when lithium-ion batteries are discharged below their safe voltage, leading to the electrolyte reacting with the electrodes, oxidizing them and possibly converting them into conductors which can lead to combustion. Similarly, if a lithium-ion battery is overcharged, the battery will heat up while charging, leading to a short circuit and potential combustion. High quality lithium-ion batteries are equipped with microchips that can prevent over-discharging or overcharging, but batteries manufactured poorly or cheaply may not include this protection.
Once a battery malfunction has occurred, it is recommended that experienced counsel be engaged promptly to evaluate and preserve the evidence in the event a product liability claim arises. Preliminary testing by knowledgeable experts can often determine the cause of the malfunction, including whether it was caused by an external or internal failure, thus narrowing the scope of potential liability and saving time and money.
3. Technological Advancements
Fueled by rising demand for batteries powering portable electronics, experts estimate that the global lithium-ion market is expected to reach $93.1 billion by 2025. Due to the inherent risks associated with lithium-ion batteries, the development of new and safer battery technologies has become an even more important and lucrative market.
Researchers are developing ways to make lithium-ion batteries safer. For example, an Internal Short Circuit (ISC) device has been developed and patented, which can cause predictable battery cell failures in lithium-ion batteries, making them easier to study, and therefore safer.[3] Specifically, the ISC can trigger cells to fail at a known location and time, which is expected to aid battery manufacturers in engineering new safety measures for their battery systems.
Relatedly, researchers at Stanford recently created a battery containing a miniature fire extinguisher, which successfully engaged during testing when the battery reached 160 degrees Celsius, preventing an explosion.[4] While that battery was designed for larger-scale use, such as in electric cars, there is potential for the technology to be applied to smaller devices such as e-cigs.
Researchers also have been developing a solid material to use in lithium-ion batteries instead of the highly flammable liquid electrolytes currently used, thereby making the batteries safer. A company in Massachusetts has developed a solid lithium polymer battery, which allows lithium ions to move as fast as or faster through its solid polymer than they can through a liquid electrolyte system with a separator.[5]
Safer alternatives to lithium-ion batteries are also being developed. Vanadium, a hard metal used to make alloy steels, is being used in a new-generation of batteries that do not heat up and are not flammable.[6] Experts believe vanadium batteries will be successful due to their extended lifespan, consistent performance over time, and safer qualities. Scientists have also developed a method to enable magnesium-metal batteries, which theoretically could contain nearly twice as much energy per volume as lithium-ion batteries and would not experience the growth of dendrites, which are whiskers of lithium that grow inside batteries over time causing devices to short out and catch fire.[7]
A company recently won an award for best technical development within energy storage at a tech show in Germany for their creation of carbon-ion cell technology to use in batteries instead of current energy storage methods, such as lithium-ion. The carbon-ion cells employ different electrolyte materials which enable them to operate at higher voltages, delivering energy densities that are more in line with current lithium-ion batteries but without any of the fire risks or safety concerns.[8]
Finally, advancements in e-cig devices, such as the development of “regulated mods,” which are equipped with certain safeguards (e.g., to shut down the device if the battery drops below the mod’s minimum voltage limit), will continue to reduce the likelihood of malfunctions.
Such technological advancements should reduce the number of product liability cases caused by malfunctioning batteries, notwithstanding the rapid expansion of the e-cig industry.
For more information about how this may affect your business and/or current or pending litigation, please contact one of the attorneys in the E-Cigarette/Vape Team.
