Temperature-responsive microcapsules alleviating the hazards of thermal runaway for lithium-ion batteries

• Published in: Applied physics letters Vol. 125; no. 2
• Main Authors: Tong, Jingjing, Peng, Yong, Liu, Jie, Wang, Li, Hou, Bowen, Feng, Xuning, Ouyang, Minggao
• Format: Journal Article
• Language: English
• Published: Melville American Institute of Physics 08-07-2024
• Subjects: Accelerated tests; Addition polymerization; Enthalpy; High temperature; Hydrates; Lithium; Lithium-ion batteries; Melamine; Microencapsulation; Product safety; Rechargeable batteries; Specific energy; Temperature; Thermal runaway
• ISSN: 0003-6951; 1077-3118
• DOI: 10.1063/5.0202495

Safety problems hinder the large-scale application of high-specific energy battery system. In this paper, a type of temperature thermo-responsive microcapsules to enhance the safety performance of lithium-ion batteries is proposed. The microcapsule is manufactured by encapsulating hydrates with melamine urea formaldehyde, and the outer shell will automatically rupture and release hydrates at ∼100 °C. It can react with the anode in advance and block reaction between the anode and the electrolyte, thereby reducing the generation of reductive gas and lowering down gas crosstalk. The thermos-responsive microcapsules are prepared by in situ polymerization, and the addition of the microcapsules could effectively reduce the reaction enthalpy by differential scanning calorimetry. Through a adiabatic accelerated calorimetry test, only 0.25 g microcapsules can increase the thermal runaway trigger temperature by 16.2 °C and reduce the maximum temperature by 117.5 °C. This innovative approach enhances the safety of high specific energy lithium-ion battery systems, providing extended thermal-runaway warning time and minimizing the hazard caused by high temperatures.