Qingling Jia, H. Li, Shun Lu, Chuanyin Xiong, Yongxing Zhang
Few‐layered 1T‐MoS 2 is highly promising for supercapacitor applications due to its wide interlayer spacing, high electrical conductivity, and abundant active sites. However, its poor structural stability greatly challenges the synthesis of stable 1T‐MoS 2 . This study systematically investigates the dual‐function mechanism of cobalt (Co) doping in few‐layered MoS 2 . Co is successfully doped into MoS 2 to fabricate stable 1T‐MoS 2 by a simple synthesis approach. The formation of Co‐S bonds during doping plays a critical role in stabilizing the 1T phase. Furthermore, Co doping deliberately induces defects in the MoS 2 lattice. The defects modify the electronic structure, increasing the density of states near the Fermi level, and enhancing both electrical conductivity and charge‐transfer efficiency. SEM, XRD, and XPS characterizations of samples stored for half a year show that Co doping stabilizes the morphology and crystal phase of 1T‐MoS 2 . DFT calculations further validate the enhanced performance of Co doping MoS 2 . Specifically, M‐Co (1.5%) (1.5% Co‐MoS 2 ) reaches a specific capacitance of 197 F g −1 at 1 A g −1 , with 88% capacitance retention after 40 000 cycles. The assembled M‐Co (1.5%)//CC asymmetric supercapacitor device maintains 92% capacity retention after 20 000 cycles. This work offers new insights into stable 1T‐MoS 2 preparation and promotes the application of TMDs in supercapacitors.