Microreactor facilitated preparation and Ni-doping of MnO2 nanoparticles for supercapacitors

K+ intercalated MnO2 with ultra-long cycling life for high-performance aqueous magnesium-ion hybrid supercapacitors

“…The formation of Mn 3 O 4 crystals should result from incomplete redox reactions. 52 Compared with MnO 2 , the (211) diffraction peak of K–MnO 2 - x at 36.5° shifts to a lower angle, indicating that the K + ions intercalated into the MnO 2 interlayer skeleton can expand the interplanar spacing, which is consistent with the HRTEM results.…”

“…The presence of the three valence states is related to the oxygen vacancies caused by the incomplete redox reaction. 52,56 It is well known that oxygen vacancies are beneficial for adjusting the electronic structure of metal oxides and ensuring fast electron transfer. 46,47 The O 1s high-resolution spectra (Fig.…”

“…† The X-intercept of the high-frequency region curve represents the ohmic resistance (R s ) of the electrolyte and electric contact. 46,52 All materials show similar R s values, indicating little effect from K + ion intercalation. The semicircle in the mid-high frequency region comes from the charge transfer resistance (R ct ) at the electrode/ electrolyte interface.…”

Co-doped MnO2 with abundant oxygen vacancies as a cathode for superior aqueous magnesium ion storage

“…[23][24][25] However, the relatively low intrinsic conductivity (10 −6 -10 −5 S cm −1 ) and the structural collapse caused by continuous charge/discharge seriously weaken the charge transfer power, resulting in the attenuation of the electrochemical performance. [26][27][28] To improve the electronic conductivity of MnO 2 and optimize its reaction kinetics, some works optimized its electronic structure by constructing heterostructures and designing special nanostructures. [29][30][31] The Mn 2 O 3 @MnO 2 composite nanofibers prepared by Lu et al 32 achieved excellent conductivity and cycling stability due to the layered core-shell structure and the synergistic effect of the two oxides.…”

Nickel-Doped Manganese Dioxide Electrocatalysts with MXene Surface Decoration for Oxygen Evolution Reaction

“…The improved electrochemical performance is attributed to the effect of enhanced electric conductivity and increased electron transport channels. However, at high concentrations, excess Ni cations tended to insert into the tunnel of MnO 2 and hindered the electron transport. , Therefore, Ni 0.075 Mn 0.925 O 2 /CC exhibited the best electrochemical performance among these four different concentrations of Ni-doped MnO 2 samples. MXene was deposited on the surface of NMO/CC; the 2D layered structure of MXene will provide more ion transport channels, which is supposed to decrease the overpotential in the OER process .…”