Battery Thermal Runaway Gas Detection Solutions: Safeguarding the Safety Line of Energy Storage Systems

In the era of new energy, energy storage battery systems have become a core driving force behind the green transition. From large-scale power grids to household backup power supplies, these systems are quietly reshaping our energy landscape. However, as battery scale expands and energy density increases, the risk of thermal runaway rises accordingly. This is not merely a technical challenge, but an urgent issue directly related to the safety of lives and property.

Traditional energy storage battery manufacturing processes often tightly weld multiple modules together, forming integrated units with high capacity and high power. Under complex operating conditions—such as high-rate charge and discharge or cooling system failures—problems such as uneven heat distribution and excessive temperature differentials frequently occur. These conditions can easily trigger thermal runaway, leading to performance degradation or even catastrophic accidents.

Imagine a densely packed battery array in which a single cell experiences an internal short circuit, causing its temperature to soar and triggering a chain reaction that releases toxic gases and leads to an explosion. This is not science fiction, but a scenario that has already occurred in reality. In response to this hidden danger, gas detection technology has emerged as an effective means of preventing thermal runaway.

This article starts with the mechanism of thermal runaway, explores the necessity of gas detection, and introduces innovative solutions under the Nexisense brand to help you build a more reliable energy storage ecosystem.

In-Depth Analysis of the Causes and Hazards of Battery Thermal Runaway

Battery thermal runaway is not a sudden event, but the inevitable result of imbalanced internal chemical reactions. In energy storage systems, the dense arrangement of large numbers of battery modules amplifies the impact of individual failures. Once heat accumulation exceeds a critical threshold, battery performance deteriorates rapidly: charging and discharging efficiency declines, capacity fades, and service life shortens.

More seriously, thermal runaway can trigger chain fires, releasing toxic gases such as hydrogen fluoride and carbon monoxide, causing long-term harm to both the environment and human health. Economic losses often reach millions, and casualties are even more tragic.

According to industry data, thermal runaway accounts for more than 70% of global energy storage accidents in recent years. This serves as a reminder that production safety cannot rely on luck. Early risk identification and proactive control are key to ensuring system stability.

Three Typical Stages of Thermal Runaway

The thermal runaway process can be divided into three progressive stages, each accompanied by rising temperatures and gas release, providing detection opportunities.

First is the internal thermal runaway stage. Triggering factors include internal short circuits, external heating, or self-heating under high-current charging and discharging. If the cooling system fails, battery temperatures can rise to 90°C–100°C. At this point, the lithium salt LiPF6 begins to decompose. Especially in a charged state, the surface solid electrolyte interface (SEI) film ruptures, and lithium ions embedded in graphite react with the electrolyte and binder, driving temperatures up to around 150°C. Further reactions between the negative electrode and the electrolyte catalyze the decomposition of organic solvents, releasing initial gases.

Second is the battery swelling stage. When temperatures exceed 200°C, the positive electrode material decomposes, releasing large amounts of heat and gas. As temperatures continue to rise to 250°C–350°C, the lithiated negative electrode reacts violently with the electrolyte. The battery casing expands and swells. During this stage, gas concentrations rise sharply, making it the golden window for early warning.

Finally is the explosive failure stage. In the charged state, the positive electrode material and electrolyte undergo oxidation reactions, instantly releasing extreme heat and gas, resulting in combustion or explosion. The entire process—from initial abnormality to disaster—can take only a few minutes, underscoring the importance of real-time monitoring.

Understanding these stages helps us design targeted detection strategies. By capturing early gas signals such as CO, H2, or volatile organic compounds (VOC), risks can be eliminated at an early stage.

The Core Role of Gas Detection in Thermal Runaway Prevention

Although current technology cannot completely eliminate lithium battery thermal runaway, achieving early warning through gas detection has become an industry consensus. During thermal runaway, intense exothermic reactions inside the battery generate large quantities of flammable and toxic gases. These gases are not only precursors to fires but can also pose direct threats to human health.

By installing gas detectors, concentration changes can be monitored in real time. Alarm thresholds can be set so that once exceeded, alarms are triggered and linked systems—such as fire suppression or isolation measures—are activated to prevent accident escalation.

In electrochemical energy storage power stations, such solutions are particularly critical. While traditional temperature monitoring is effective, gas detection is more sensitive and can capture chemical signals before temperature anomalies occur. Combined with big data analysis, systems can predict potential risks and enhance overall safety. Practical experience shows that energy storage projects equipped with gas detection systems experience significantly lower accident rates.

Nexisense Innovative Gas Detection Solutions

As a leading brand specializing in gas sensing technology, Nexisense has launched the NS-506 series fixed multi-gas detectors, backed by years of expertise. This product is designed for multi-gas monitoring needs and supports flexible combinations of 1–6 gases, including CO, H2, CH4, VOC, and other common thermal runaway components.

Detection ranges and sampling methods are flexible, supporting long-distance sampling and rapid analysis. The NS-506 features a built-in brushless vacuum sampling pump, operates on a default 12–30V power supply, and enables 24/7 online monitoring.

When concentrations exceed thresholds, the system automatically activates audible and visual alarms and uses built-in relays to link external devices such as ventilation systems or fire sprinklers to promptly eliminate hazards. It also supports 4–20mA analog output or RS485 digital signal transmission, making integration into battery management systems (BMS) convenient.

Additionally, the system can be expanded to monitor temperature, humidity, PM2.5, and PM10, providing comprehensive environmental data.

In energy storage applications, the NS-506 can be installed inside battery cabins or containers, with thresholds configured based on thermal runaway characteristics. For example, a first-level alarm can be triggered when CO concentration exceeds 50 ppm, while excessive H2 levels can activate emergency isolation. This multi-parameter fusion not only improves detection accuracy but also reduces false alarms, ensuring efficient system operation.

Nexisense products emphasize durability and compatibility, making them suitable for a wide range of energy storage scenarios—from commercial power stations to industrial backup power systems. With easy installation and low maintenance costs, they help users build an intelligent safety network.

Practical Benefits and Case Studies of Implementing Gas Detection Solutions

Introducing gas detection is not an additional burden, but a high-return safety upgrade. The benefits are clear: first, early risk control reduces accident losses; second, system optimization is achieved through data feedback, improving cooling and layout design; third, compliance is ensured, meeting international standards such as UL 9540 and NFPA 855.

In one large photovoltaic energy storage project, the system initially lacked gas monitoring and experienced module overheating due to uneven heat distribution. After introducing the Nexisense NS-506, real-time data helped optimize ventilation strategies, controlling temperature differentials within 5°C and reducing gas anomaly alarm rates by 90%.

In another industrial case, the detector captured rising VOC levels during the battery swelling stage, enabling timely isolation of the faulty battery and preventing a potential explosion.

These cases demonstrate that gas detection is not merely a technical supplement, but a cornerstone of sustainable energy storage development.

Frequently Asked Questions (FAQ)

1. What is battery thermal runaway? Battery thermal runaway refers to the loss of control of internal chemical reactions, leading to rapid temperature rise, gas release, and potentially fire or explosion.

2. Which gases can thermal runaway gas detectors monitor? Common gases include CO, H2, CH4, and VOC, with customizable combinations based on energy storage system characteristics.

3. What is the difference between gas detection and temperature monitoring? Gas detection captures chemical signals earlier, while temperature monitoring lags behind reaction onset, making gas detection more suitable for early warning.

4. Which scenarios are the NS-506 series suitable for? It is suitable for electrochemical energy storage power stations, commercial battery systems, industrial backup power supplies, and supports both indoor and outdoor installation.

5. How are alarm thresholds set? Based on battery type and operating conditions, such as CO at 50 ppm and H2 at 1000 ppm, optimized using historical data.

6. How much investment is required to install gas detectors? This depends on system scale, but the payback period is typically less than one year due to reduced accident losses.

7. How are detectors integrated into existing BMS? Seamless connection via RS485 or 4–20mA signals, supporting standard protocols such as Modbus.

8. How do detectors respond during thermal runaway? They automatically trigger alarms and link devices such as power shutdown or fire suppression systems to minimize damage.

9. What are the unique advantages of Nexisense products? Flexible multi-parameter combinations, long-distance sampling, strong expandability, and a focus on energy storage safety applications.

10. How are gas detectors maintained? Regular sensor calibration and inspection every 6–12 months to ensure accuracy and reliability.

Conclusion: Building a Safer Energy Storage Future

Battery thermal runaway gas detection solutions are not only technological innovations, but also a reflection of responsibility. As the energy storage industry develops rapidly, safety must always remain the top priority.

Through professional equipment from brands such as Nexisense, potential hazards can be identified early and risks effectively mitigated, making systems more stable and environments more sustainable. Enterprises should not rely on luck, but proactively adopt these tools to achieve early detection and early control.

Ultimately, making human living and working environments safer and more environmentally friendly is Nexisense’s mission and pursuit. Choose reliable detection solutions and start protecting your energy storage assets today.