Energy Storage 3.0 Era: How to Build a Strong Fire Safety Defense Line?

With the acceleration of the “dual carbon” goals and the in-depth construction of new power systems, electrochemical energy storage installed capacity is showing explosive growth worldwide. In 2025, China’s new energy storage cumulative installed capacity has exceeded 100 GW, and it is expected to continue high-speed growth in 2026. At the same time, lithium-ion battery energy storage systems, due to their high energy density and high integration, are extremely prone to evolving into fire or even explosion accidents once thermal runaway occurs. Multiple domestic and international energy storage power station fire incidents in recent years have sounded the alarm: how to truly achieve “early detection, early warning, early disposal” in the Energy Storage 3.0 era has become a core proposition that the industry must face head-on.

Nexisense has long focused on gas perception and safety monitoring technology. The independently developed FC-CO-5000 carbon monoxide sensor and FC-H2-5000 hydrogen sensor are key components born precisely against this background. Based on solid-state electrolyte technology, they provide precise, stable, and long-term monitoring of the early characteristic gases (CO and H₂) of lithium battery thermal runaway, offering a reliable technical fulcrum for the fire safety of energy storage systems.

The Essence of Lithium Battery Thermal Runaway and the Evolution Path of Early Characteristic Gases

Lithium-ion battery thermal runaway is not an instantaneous event but a multi-stage, chain-reaction process:

1. Initial abuse stage (overcharge/overdischarge, short circuit, external high temperature, etc.) The internal SEI film decomposes, and the electrolyte begins mild redox reactions, producing a small amount of heat and gas.

2. Self-heating acceleration stage Temperature continues to rise, cathode material decomposes releasing oxygen, electrolyte decomposes violently, producing a large amount of combustible gases (H₂, CO, CH₄, C₂H₄, etc.), with heat rapidly accumulating.

3. Thermal runaway eruption stage Battery casing ruptures, high-temperature high-pressure gas and flames erupt, accompanied by severe combustion and re-ignition risks.

Analysis of a large number of cases shows that hydrogen (H₂) usually begins significant release in the early stage of thermal runaway (temperature about 120–180℃), while carbon monoxide (CO) concentration rises rapidly in the 180–220℃ range. These two gases are recognized as “precursor characteristic gases of thermal runaway.” Therefore, achieving ppm-level early detection of H₂ and CO inside battery compartments is currently one of the most effective and economical fire prevention methods.

Core Requirements of Energy Storage Fire Protection and Limitations of Existing Solutions

Current energy storage power station fire protection schemes mainly revolve around four links: “sensing—alarm—extinguishing—smoke exhaust,” but in actual deployment, several major pain points remain:

• Sensing lag: Traditional smoke/temperature detectors respond slowly to concealed thermal runaway;

• High false alarm rate: Some gas sensors are susceptible to interference from siloxane volatiles, cleaners, and oil-gas;

• Lifespan vs. maintenance contradiction: Many sensors show significant performance degradation after 3–5 years, with high maintenance costs;

• Corrosion and secondary risks: Some fire extinguishing media or sensor leakage may corrode high-value batteries and PCS equipment;

• Integration compatibility: Sensor output protocols from different manufacturers are not uniform, making system interfacing complex.

The Nexisense FC-CO-5000 and FC-H2-5000 series are systematic optimization solutions precisely targeting the above pain points.

Key Value of Nexisense Dual Sensors in Energy Storage Fire Protection

FC-H2-5000 Hydrogen Sensor

• Adopts solid-state electrolyte + targeted reduction-method selective catalyst, showing extremely high specificity for H₂;

• Range 0–1000 ppm, detection limit as low as 5 ppm, capturing hydrogen release at very early thermal runaway stages;

• Strong resistance to silicon poisoning, ethanol/formaldehyde/hydrogen sulfide interference, suitable for complex gas environments in battery compartments;

• Operating temperature -40℃～+70℃, lifespan over 10 years, factory self-contained calibration data, no need for on-site secondary calibration;

• Ultra-small button-type package (weight only 3g), convenient for dense array deployment.

FC-CO-5000 Carbon Monoxide Sensor

• Also based on solid-state electrolyte technology, no liquid electrolyte, no leakage risk;

• Range 0–1000 ppm, linear output, response time<30 s;

• Excellent performance against interfering gases such as siloxanes, ethanol, formaldehyde, significantly reducing false alarm rate;

• Lifespan 5–10 years, wide temperature -20℃～+60℃, suitable for outdoor container cabins and indoor battery rooms;

• Supports standard analog current output, easy to access existing fire hosts or BMS systems.

Synergistic Advantages of Both

• H₂ early warning (very early) → CO confirmation escalation (mid-early) → temperature/smoke final confirmation, forming a multi-level progressive warning logic;

• Both sensors are non-corrosive, non-conductive media, meeting energy storage cabin “non-corrosive, non-toxic, non-conductive” fire protection requirements;

• Supports direct connection to mainstream energy storage fire extinguishing systems such as aerosol, water mist, fluorinated liquid, hot aerosol, achieving a “detection-alarm-extinguishing” closed loop.

Deployment Recommendations in Engineering Practice

1. Deployment Strategy

• Install 1–2 FC-H2-5000 units on the top or side wall of each battery cluster (priority to capture hydrogen);

• Add FC-CO-5000 in the middle of the cabin and near exhaust vents (monitor CO accumulation);

• Set backup CO monitoring points on the top or door side of the external container.

2. System Integration

• Sensor 4–20 mA standard current output, directly connected to fire controller or BMS analog input channel;

• Recommended multi-level thresholds: H₂ 50 ppm warning, 100 ppm alarm; CO 30 ppm warning, 100 ppm linked extinguishing.

3. Maintenance and Lifespan Management

• Factory self-contained calibration QR code, scan to read remaining lifespan and health status;

• Recommended functional verification every 12 months, no gas calibration required.

FAQ: Common Professional Questions from Integrators, Procurement, and Engineers

Q1: Will FC-H2-5000 and FC-CO-5000 interfere with each other inside the energy storage cabin?
Nexisense Engineer: The two sensors use different targeted catalyst formulations, with extremely low cross-sensitivity (<1%). Actual tests show that in typical thermal runaway gas mixture environments, H₂ sensor response to CO <0.5%, CO sensor response to H₂ <1%, enabling independent and reliable monitoring.

Q2: Will solid-state electrolyte sensors fail or drift in high-humidity energy storage cabins?
Nexisense Technical Support: The product internally uses dynamic moisture-locking microstructure, maintaining electrolyte activity in the 15%–95% RH range. After accelerated aging test (85℃/85%RH, 1000 h), zero-point drift <±5 ppm, sensitivity change <±10%, fully meeting long-term outdoor container cabin usage requirements.

Q3: How to achieve fast linkage between the sensors and existing aerosol/fine water mist extinguishing systems?
Nexisense Procurement Reference: Sensor 4–20 mA current signal can be directly connected to the analog input module of the fire controller. Recommended dual-threshold logic: H₂>80 ppm or CO>80 ppm triggers level-1 alarm, H₂>150 ppm or CO>150 ppm outputs relay closure signal to directly link extinguishing device, response time<2 s.

Q4: How to ensure consistency and interchangeability of sensors from different batches during bulk procurement?
Nexisense Engineer: Every sensor undergoes 100% calibration before shipment, with calibration data solidified in QR code and internal memory. Zero-point and sensitivity consistency between batches controlled within ±5%. Recommended that integrators establish incoming inspection system (zero point, 100 ppm response, interference test) and retain QR code data for later traceability.

Q5: Can FC-H2-5000 maintain long-term effectiveness in battery cabins containing silicone sealant?
Nexisense Technical Support: The catalyst adopts an anti-siloxane poisoning optimized formulation, with sensitivity attenuation<10% after 500 ppm Decamethylcyclopentasiloxane (D5) exposure test. Actual customer feedback shows that in containers using large amounts of silicone sealing, the sensor still maintains normal alarm function after more than 3 years of operation.

Q6: How to prove the sensor’s reliability and compliance to owners during energy storage project bidding?
Nexisense Market Support: Complete product test reports (GB/T 36276, EN50291, UL2034 component-level certification), third-party testing agency reports, accelerated life test data, and commissioned project cases can be provided. Recommended to explicitly list in the technical proposal “10-year lifespan commitment + calibration-free design + anti-silicon poisoning verification,” and attach QR code calibration data reading examples for quick verification by review experts.

Conclusion

In the Energy Storage 3.0 era, safety is no longer an add-on but a core competitiveness. Nexisense FC-CO-5000 carbon monoxide sensor and FC-H2-5000 hydrogen sensor, with solid-state anhydrous technology, anti-poisoning catalyst, and ppm-level early detection capability as core, build a solid “gas-phase defense line” for lithium battery energy storage systems. They not only significantly improve the timeliness and accuracy of fire warning but also eliminate leakage and false alarm hazards of traditional sensors from the design source, providing truly implementable and trustworthy fire perception solutions for integrators, EPC contractors, and power station owners.

In the future, as energy storage scale continues to expand and technology iterates rapidly, Nexisense will continue to deeply cultivate characteristic gas perception field, working together with upstream and downstream of the industry chain to promote the new standard of energy storage safety featuring “earlier perception, faster response, smaller losses.”

If you need detailed specification sheets, prototype testing, certification files, or project cases, please feel free to contact the Nexisense technical and sales team. We look forward to partnering with you to safeguard global clean energy infrastructure.