Ultrasensitive Hydrogen Sensor Based on a Non-Stoichiometric Tin Oxide Heterojunction for LIB Thermal Runaway Early...

Area of Science:

• Materials Science
• Chemical Sensing
• Energy Storage Safety

Background:

• Real-time hydrogen (H2) detection is vital for early thermal runaway warnings in devices like lithium-ion batteries.
• Conventional semiconductor metal oxide sensors struggle with low H2 sensitivity due to weak molecule-surface interactions.

Purpose of the Study:

• To develop an enhanced sensor for sensitive, real-time detection of trace hydrogen gas.
• To improve early warning capabilities for thermal runaway events in lithium-ion batteries.

Main Methods:

• Modification of SnO/Sn2O3 with palladium (Pd) sensitizers to create Pd-doped sensors.
• Characterization of sensor performance, including sensitivity and detection limits at elevated temperatures.
• Validation of the sensor's effectiveness in a commercial lithium-ion battery pack.

Main Results:

• The optimized 1 wt% Pd-doped SnO/Sn2O3 sensor achieved a high response to 50 ppm H2 at 180 °C.
• An ultralow theoretical detection limit of 0.35 ppb for H2 was recorded.
• In practical tests, the sensor provided thermal runaway warnings approximately 28 minutes earlier than standard battery management systems.

Conclusions:

• Palladium sensitization significantly enhances the H2 sensing performance of SnO/Sn2O3.
• Synergistic effects, including defects, Pd-induced spillover, and heterojunction interfaces, contribute to superior sensing.
• The developed sensor shows strong potential for real-time safety monitoring in lithium-ion batteries.