Flower-like manganese and phosphorus co-doped MoS2 with high 1T phase content as a supercapacitor electrode material

Abstract

Molybdenum disulfide (MoS₂) usually exhibits a severe stacking and agglomeration phenomenon, and an inferior rate capability and cyclability as a supercapacitor electrode material. Heteroatom doping and phase engineering are the available methods to ameliorate the electrochemical performances of MoS₂. Herein, flower-like manganese and phosphorus co-doped MoS₂ (MnP–MoS₂) is successfully fabricated via using manganese chloride and sodium hypophosphite as dopants. The obtained MnP–MoS₂ possesses a large interlayer spacing of 0.88 nm and a high 1T phase content of 82.9%. Thanks to the synergistic doping effect of Mn and P, MnP–MoS₂ delivers a maximum capacity of 432.3 F g⁻¹ at 1 A g⁻¹ and maintains 55.7% of the initial capacity at 20 A g⁻¹. Moreover, the asymmetric supercapacitor (ASC) device fabricated using MnP–MoS₂ as the positive electrode and activated carbon (AC) as the negative electrode displays an energy density of 16.7 W h kg⁻¹ at 403.9 W kg⁻¹, and keeps 84.4% of the original capacity after 2000 cycles. This work proposes a versatile strategy to develop other two-dimensional transition metal chalcogenides as high-performance electrode materials for supercapacitors.