10.1038/srep14146
Membranes of MnO Beading in Carbon Nanofibers as Flexible Anodes for High-Performance Lithium-Ion Batteries
Polyacrylonitrile (PAN, Mw = 80000) was made in laboratory52. Potassium permanganate (KMnO4, AR), sulfuric acid (H2SO4, AR) and N,N-dimethylformamide (DMF, AR) were purchased from Shanghai Lingfeng Chemical Reagent Co., Ltd. Manganese sulfate monohydrate (MnSO4*H2O, AR) was purchased from Sinopharm Chemical Reagent Co., Ltd. All these reagents were used without further purification. 
MnO2 NWs were synthesized by a hydrothermal method. Briefly, aqueous solutions of MnSO4*H2O (1 mmol) and KMnO4, (1.5 mmol) (Mn(II)/Mn(VII) = 3:2) were mixed with vigorously stirring. The PH value of the mixture was adjusted ~2 with 5 M H2SO4 aqueous solution. Then the solution was transferred to an autoclave and reacted in oven at 140 degC for 12 h. After cooling down, the product was collected by filtration and washed repeated with distilled water and absolute ethanol. Then the MnO2 NWs powder was obtained. 
The obtained MnO2 NWs powder was washed three times with DMF, centrifuged and then added into a certain-mass 8 wt% PAN/DMF solution as an electrospinning solution. Intensive stirring was conducted for 12 h in order to get a homogeneously distributed solution. Then the blended solution was electrospun into MnP membranes, with a controlled syringe pump of 25 μL min-1 and an applied voltage of 20 kV with a distance of 20 cm between the electrospinning jet and the collector. The adding amounts of MnO2 NWs based on PAN were 10 wt%, 20 wt% and 30 wt% for MnP-1, MnP-2 and MnP-3, respectively.
Polyacrylonitrile (PAN
Mw = 80000
Mw
KMnO4
mixed with vigorously stirring
1.5 mmol
mmol
MnSO4*H2O
mixed with vigorously stirring
1 mmol
mmol
Mn(II)/Mn(VII)
mixed with vigorously stirring
3:2
mixture
PH value
~2
H2SO4 aqueous solution
5 M
M
solution
reacted
140 degC
degC
solution
reacted
12 h
h
PAN/DMF solution
MnO2 NWs powder
8 wt%
wt%
obtained MnO2 NWs powder
washed
three times
times
Intensive stirring
12 h
h
blended solution
electrospun
25 μL min-1
μL min-1
blended solution
electrospun
20 kV
kV
electrospinning jet and the collector
distance
20 cm
cm
MnP-1
adding amounts
10 wt%
wt%
MnP-2
adding amounts
20 wt%
wt%
MnP-3
adding amounts
30 wt%
wt%