School of Energy and Environment, City University of Hong Kong, 83 Tat Chee Avenue, Kowloon, P. R. China.
ChemSusChem. 2023 Feb 20;16(4):e202201221. doi: 10.1002/cssc.202201221. Epub 2022 Sep 2.
The increasing number of accidents relating to battery fire and explosion is raising people's attention towards safety of batteries. Abnormal battery operation can generate much heat and cause thermal runaway due to the exothermic reactions of the electrodes and electrolyte. Recently, dual-ion battery (DIB) has gained many interests because of its low cost and high working voltage compared with traditional lithium-ion battery (LIB). However, investigation on thermal stability of DIB is rare. In this paper, differential scanning calorimetry (DSC) was used to study the thermal stability of DIB using graphite as cathode with different states of charge (SOC) and with different amount of fluoroethylene carbonate as co-solvent in the electrolyte. Then, the thermal stability of graphite cathode for DIB was compared with those of LiCoO and LiNi Mn O at their fully charged states. Specifically, charged DIB using graphite as cathode in 3 m LiPF EMC showed superior thermal stability with no exothermic peaks in DSC tests, in contrast to traditional lithium-containing cathodes for LIB, which gave out significant amount of heat at evaluated temperature. In addition, the thermal stability of graphite depended on the type of intercalation species in it. While PF intercalated graphite [C (PF )] showed an endothermic peak at about 320 °C, Li intercalated graphite [C (Li)] showed an exothermic peak at about 300 °C. Moreover, the type of electrolyte also affected heat generation from the charged electrodes and should be properly designed to improve thermal stability in the future.
越来越多的与电池火灾和爆炸有关的事故引起了人们对电池安全性的关注。异常的电池运行会产生大量热量，并由于电极和电解质的放热反应而导致热失控。最近，由于与传统的锂离子电池（LIB）相比具有低成本和高工作电压，双离子电池（DIB）引起了广泛关注。然而，对 DIB 的热稳定性的研究很少。在本文中，使用差示扫描量热法（DSC）研究了不同荷电状态（SOC）的石墨作为阴极的 DIB 的热稳定性，并研究了电解质中不同氟代碳酸乙烯酯（FEC）用量的 DIB 的热稳定性。然后，将 DIB 石墨阴极的热稳定性与 LiCoO 和 LiNi Mn O 在完全充电状态下的热稳定性进行了比较。具体而言，在 3 m LiPF EMC 中使用石墨作为阴极的充电 DIB 在 DSC 测试中没有放热峰，表现出优异的热稳定性，与传统的 LIB 用含锂阴极相比，在评估温度下会释放出大量热量。此外，石墨的热稳定性取决于其中嵌入的插层物种的类型。虽然 PF 嵌入石墨 [C（PF ）] 在约 320°C 处表现出吸热峰，但 Li 嵌入石墨 [C（Li）] 在约 300°C 处表现出放热峰。此外，电解质的类型也会影响充电电极产生的热量，应适当设计以提高未来的热稳定性。
