检测磷酸铁锂电池热失控气体C_(2)H_(4)的MoS_(2)@c-MOF传感器研究

MoS2@c-MOF sensor for detecting thermal runaway gas C_(2)H_(4)in lithium iron phosphate batteries

磷酸铁锂电池由于其固有的放热特性以及在电解液中使用易燃有机溶剂,存在着巨大的热失控风险,可能引发严重的火灾事故,因此对磷酸铁锂电池热失控气体的实时监测已成为当前研究的重点。针对目前SnS_(2)/MoS_(2)气体传感器存在工作温度高、灵敏度低等难题,基于导电金属有机框架c-MOF在提升导电性能和增强选择性方面的独特优势,开展了SnS_(2)/MoS_(2)@c-MOF气敏材料制备、C_(2)H_(4)传感特性及检测机理研究。首先利用水热法成功制备了SnS_(2)@c-MOF和MoS_(2)@c-MOF复合气敏材料,并利用XRD和SEM表征手段验证了复合气敏材料的成功制备。然后,制成了平面式SnS_(2)@c-MOF和MoS_(2)@c-MOF传感器,测试了传感器对C_(2)H_(4)的浓度响应、响应恢复时间和稳定性。结果表明,MoS_(2)@c-MOF传感器对10ppm C_(2)H_(4)气体的响应值为4.42%,响应时间/恢复时间为121 s/124 s,优于SnS_(2)@c-MOF传感器,同时具有较好的长期稳定性。最后,基于密度泛函理论,从吸附能、吸附距离、态密度和电荷转移角度对比分析了SnS_(2)@c-MOF和MoS_(2)@c-MOF材料对C_(2)H_(4)的吸附性能和响应特性。本文研究成果为开发用于检测磷酸铁锂电池热失控产生的C_(2)H_(4)气体的高性能MoS_(2)@c-MOF传感器奠定了基础。

Lithium-iron phosphate batteries pose significant thermal runaway risks due to their exothermic nature and the use of the flammable organic solvents in the electrolytes,potentially leading to severe fire accidents.Real-time monitoring of the thermal runaway gases from lithium-ion phosphate batteries has thus become a focal point of current research.Aiming at the challenges such as high operating temperatures and low sensitivity in SnS_(2)/MoS_(2)gas sensors,this study leverages the unique advantages of conductive metal-organic frameworks(c-MOFs)in enhancing conductivity and selectivity.SnS_(2)/MoS_(2)@c-MOF gas-sensitive materials were synthesized and investigated for ethylene(C_(2)H_(4))sensing characteristics and detection mechanisms.Initially,SnS_(2)@c-MOF and MoS_(2)@c-MOF composite sensing materials were successfully prepared via hydrothermal methods,as confirmed by XRD and SEM characterization.Planar SnS_(2)@c-MOF and MoS_(2)@c-MOF sensors were fabricated and evaluated for their response to C_(2)H_(4)concentration,response time and recovery time,and long-term stability.The results indicate that the MoS_(2)@c-MOF sensor exhibits a response of 4.42%to 10ppm C_(2)H_(4)gas,with response and recovery time of 121 s and 124 s,respectively,which is better than that of the SnS_(2)@c-MOF sensor and it demonstrates superior long-term stability.Furthermore,density functional theory was employed to compare and analyze the adsorption properties and response characteristics of SnS_(2)@c-MOF and MoS_(2)@c-MOF materials towards C_(2)H_(4)from the perspectives of adsorption energy,adsorption distance,density of states,and charge transfer.The findings of this study lay the foundation for the development of high-performance MoS_(2)@c-MOF sensors designed to detect C_(2)H_(4)gas emission during thermal runaway in lithium iron phosphate batteries.