Lithium-ion batteries power products and applications across every industry, but their use in electric vehicles (EV) drive even greater dependence on this technology. Though millions of dollars pour into research and development projects related to lithium-ion energy storage each year, these systems remain vulnerable to a phenomenon that occurs across every type of battery: thermal runaway. Amphenol Sensors offer EV owners a powerful tool for earlier detection of this devastating phenomenon.
What is Thermal Runaway
From electric vehicles to everyday personal electronics, such as cell phones and laptop computers, demand for Lithium-ion batteries continues to grow. Since their introduction in 1991, research and development evolved lithium-ion battery technology into a reliable energy storage solution. One key area of research revolves around thermal runaway.
Thermal runaway is an exothermic reaction that can occur in any type of battery. Exothermic reactions are those that produce heat. The circular process occurs when the heat generated by a lithium-ion battery exceeds the amount of heat the battery can quickly and safely dissipate to its surroundings. Though the phenomenon often results from damage or environmental factors that include high temperature, thermal runaway drives the release of heat beyond what external factors produce. At this threshold, the process becomes self-sustaining. The cells within the battery continue to generate heat unchecked, progressively worsening until a catastrophe occurs or something is done to remedy the situation.
Engineers have long respected the thermodynamic principles behind thermal runaway. The increasing popularity of electric vehicles and other electronic devices, such as cell phones and hoverboards, brought this issue to the forefront of public attention in recent years.
Thermal Runaway Process in Lithium-Ion Batteries
Though thermal runaway can occur with any type of battery, the phenomenon raised serious safety concerns in recent years as reliance on lithium-ion batteries grows.
When a cell is damaged, such as by overcharging, crushing, or overheating, the typical electrochemical reactions within the cell that are necessary for normal operation give way to chemical reactions. These chemical reactions produce toxic, flammable gasses and heat. That resulting heat drives the reaction to continue.
The heat from a single damaged cell dissipates into the cell’s surroundings. As that heat accumulates, it begins to damage nearby cells. Through this process, thermal runaway develops in nearby cells, compounding heat and gasses produced and driving the reaction faster.
This destructive thermal process poses an incredible risk to owners. Toxic gases are emitted into the environment. Additionally, these flammable gases are also the leading cause of EV vehicle fires.
What Triggers Thermal Runaway?
Thermal runaway results from a variety of environmental factors and damage.
For EV owners, the likeliest culprits include:
- Internal short-circuits
- High temperatures
- Storm flooded vehicles
Dangers of Uncontrolled Thermal Runway
Once thermal runaway begins, the process does not stop on its own. The dangers of this runaway train include vehicle damage as well as risk to drivers and occupants.
Thermal Runaway damages EV batteries. Potential consequences of thermal runaway include:
- Melted battery
- EV system failure
- Gas explosion and fire
Thermal runaway is the leading cause of fire in electrical vehicles. Adding to this serious risk, the process progresses very quickly and with very little external warning in some cases. EV battery fires begin within the enclosed battery, complicating efforts to extinguish the fire at its root. Such fires pose elevated risk to emergency professionals called to assist.
Thermal Management And Preventative Maintenance Promote EV Battery Health
Traditional gas-powered vehicles require regular maintenance for optimal operation. Regular oil changes, for example, extend the life of an engine. In fact, a history of regular oil changes is often touted by pre-owned car dealers as a predictor of both vehicle quality and life expectancy.
For the Electric Vehicle market, however, new terms and considerations replace traditional gas-powered maintenance tasks such as oil changes. For EV owners, thermal management offers the best way to protect and extend the life of your EV engine.
EV batteries boast an impressive service life. Batteries last anywhere between 12 and 15 years. Advancing technology within modern EV lithium-ion batteries lasts over 300 miles between charges and requires very little maintenance. Thermal management and responsible charging habits, however, ensure owners achieve the longest battery life and most consistent performance.
Smart Habits for EV Owners
Protecting battery life and EV performance steps are smart habits that help EV owners enjoy their vehicles for as long as possible. Thermal management and battery maintenance tips include:
- Limit reliance on fast chargers. Fast chargers offer invaluable convenience over long road trips, but regular use degrades an EV battery pack quicker than 120- or 240-volt charging devices.
- Avoid charging your EV battery to 100% or allowing the battery to drain completely. Both of these conditions degrade EV batteries quickly.
- Regularly inspect tires for wear and tear. Routinely scheduled rotation and balancing optimizes energy efficiency and to extend the time between charges.
Preventative maintenance may help extend the life of an electric vehicle, but preventative maintenance won’t stop thermal runaway once it has begun. Considering the devastating consequences, early detection is the best way to identify, treat, and mitigate the costly effects of thermal runaway on your EV’s lithium-ion battery.
Earlier Detection Is Critical to Avoid Catastrophe
Until recently, EV owners relied on battery protection sensors capable of detecting catastrophic battery failure once the chain reaction was well on its way. These sensors monitor the temperature, electrical current, and voltage within a battery. Unfortunately, the reactions occurring within a single damaged cell happen very quickly. A battery is already dangerously damaged by the time the sensors register significant enough changes in temperature, current, or voltage worth signaling an alarm. The unpredictable nature of thermal runaway means that combustion and fire may be an EV owner’s first indication of an issue.
An earlier indication of battery damage offers EV owners the best odds of preventing costly damage. Amphenol Advanced Sensors offers EV owners an innovative new sensor technology capable of robust and early detection of thermal runaway. These new sensors adopt a novel approach to thermal runaway detection. They measure gasses emitted when a lithium-ion cell is damaged rather than traditional temperature, current, and voltage measurements.
New Approach to Thermal Runaway Detection with Amphenol REDTR
Amphenol incorporates thermal conductivity sensors to detect Hydrogen in their new thermal runaway solution, REDTR. Short for Robust Early Detection of Thermal Runaway, this solution hit the market in 2020. It is available in both a standalone device as well as a sensor system designed for integration into the battery management system architecture. Amphenol’s system responds to gas venting from a single point within a lithium-ion battery pack regardless of the battery’s cell size, configuration, or electrochemistry.
With its innovative techniques for monitoring ejecta plume from a damaged cell, the REDTR system identifies the initial cell vent within seconds. This advanced system, however, goes one step further. It features the ability to qualify an emission event as contained or cascading. The combination of earlier warnings and information about the degree to which thermal runaway has spread offers EV owners critical time for the safety measures that protect their vehicles and prevent physical injury.
To learn more about the Amphenol REDTR system, visit Amphenol Sensors’ Thermal Runaway Resource Hub.
Amphenol Advanced Sensors, part of the Amphenol Corporation portfolio of brands, drives innovation in sensor technology and capability.
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