Doping-Regulated Positive Induction of Conductive Filaments in a CNTs/ZnAl-LDHs/ITO Gasistor for Ultrasensitive DMC Detection

High-performance dimethyl carbonate (DMC) sensors are critical for early warning of lithium iron phosphate battery thermal runaway. Compared to traditional thin-film sensors, gasistors have exhibited unique performance advantages. However, due to the lack of optimized regulation, current conductive filaments (CFs) in gasistors exhibit high randomness, making it difficult to ensure the stability of recognition functions. Herein, we proposed a novel approach to regulate gasistor performance by doping positively induced CF configurations. First-principles calculations show that Al atoms can significantly enhance the migration capability of oxygen vacancies (Ov) by regulating the electronic structure and distribution of the substrate, realizing the controlled formation of CFs. Further molecular dynamics simulations indicate that the high resistive state substrate exhibits good DMC adsorption and anti-interference performance. Atomic-resolution AC-TEM images clearly demonstrate the consistency between theoretical models and synthesized samples, and the deviation in stoichiometric ratios also suggests a positive induction effect of Al atoms on Ov CFs. Developed CNTs/ZnAl-LDHs/ITO gasistor exhibits a 28.4 response to 1 ppm DMC at room temperature with a recovery time of ∼1 s, response deviation and humidity stability both below 2%. Besides, stable responses under both single and mixed gas conditions demonstrate excellent DMC selectivity. Finally, a modified parallel model was proposed to elucidate synergistic mechanisms, while COMSOL simulations linked Joule heating to anti-humidity and rapid recovery.