Electrochemistry Application — Construction of hierarchical nickel cobalt selenide complex hollow spheres for pseudocapacitors with enhanced performance

5 measurement groups · 33 results

Reported values remain attached to the sample, method, conditions, extraction quality and source location that produced them.

CV and galvanostatic charge-discharge

Voltammetry Galvanostatic cycling

activated carbon negative electrode · Electrode

Commercial active carbon electrode measured in a three-electrode system; SI Fig. S7 shows CV and GCD curves.

Geometry: active carbon negative electrode
Context: negative electrode component for ASC
Measurement source: 9 · Supplementary data · Fig. S7

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
active carbon CV potential window	approximately -1.0 to 0.0 V vs Hg/HgO	1 V	visual estimate from clipped SI Fig. S7 axis	Figure Axis Approximate	9 · Figure inspection · Fig. S7a
active carbon CV scan-rate series	5, 10, 20, 40 and 60 mV s-1	—	—	Figure Axis Exact Reported	9 · Figure inspection · Fig. S7a

two-electrode ASC CV, GCD, cycling and Ragone analysis

Voltammetry Galvanostatic cycling

(Ni0.33Co0.67)Se2 CHSs//AC ASC device · Electrode

(Ni0.33Co0.67)Se2 CHSs positive electrode; activated carbon negative electrode; selected 0-1.6 V device window

Geometry: asymmetric supercapacitor device
Context: application device
Measurement source: 114-115 · 3. Results and discussion · Fig. 6

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
ASC specific capacitance at 1 A g-1Marked as a best value within this paper	81.9 F g-1 at 1 A g-1	81.9 F g-1	—	Text Exact Reported	115 · 3. Results and discussion · Fig. 6d
ASC specific capacitance at 2 A g-1	approximately 77 F g-1 at 2 A g-1 from Fig. 6d	77 F g-1	visual estimate, roughly +/-3 F g-1	Visual Estimate Approximate	114 · Figure inspection · Fig. 6d
ASC specific capacitance at 4 A g-1	approximately 72 F g-1 at 4 A g-1 from Fig. 6d	72 F g-1	visual estimate, roughly +/-3 F g-1	Visual Estimate Approximate	114 · Figure inspection · Fig. 6d
ASC specific capacitance at 6 A g-1	approximately 68 F g-1 at 6 A g-1 from Fig. 6d	68 F g-1	visual estimate, roughly +/-3 F g-1	Visual Estimate Approximate	114 · Figure inspection · Fig. 6d
ASC specific capacitance at 8 A g-1	64.8 F g-1 at 8 A g-1	64.8 F g-1	—	Text Exact Reported	115 · 3. Results and discussion · Fig. 6d
ASC cycling stability	no obvious capacitance loss after 5000 cycles	—	—	Text Qualitative	115 · 3. Results and discussion · Fig. 6e
ASC energy density at 6400 W kg-1	23.0 Wh kg-1 at 6400 W kg-1	23 Wh kg-1	—	Text Exact Reported	115 · 3. Results and discussion · Fig. 6f
ASC energy density at 800 W kg-1Marked as a best value within this paper	29.1 Wh kg-1 at 800 W kg-1	29.1 Wh kg-1	—	Text Exact Reported	115 · 3. Results and discussion · Fig. 6f
ASC potential windows tested	1.4, 1.5, 1.6 and 1.7 V at 30 mV s-1	—	—	Figure Axis Exact Reported	114 · Figure inspection · Fig. 6a
ASC CV scan-rate series	5, 10, 20, 40, 60 and 80 mV s-1	—	—	Figure Axis Exact Reported	114 · Figure inspection · Fig. 6b
selected ASC voltage window	0-1.6 V	1.6 V	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 6a

SI literature-comparison table

(Ni0.33Co0.67)Se2 CHS working electrode · Electrode

Table S1 compares the reported (Ni0.33Co0.67)Se2 CHS capacitance and mass loading with other Ni/Co selenide electrodes.

Geometry: three-electrode active-material electrode
Context: target electrode compared with literature values
Measurement source: 3-4 · Supplementary data · Table S1

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Table S1 literature-comparator capacitance range	approximately 413.8-759.0 F g-1 across listed comparator electrodes	—	range summarised from SI Table S1 comparator rows	SI Table Range	3-4 · Supplementary data · Table S1
Table S1 mass loading for reported electrode	1~2 mg	—	range 1-2 mg	SI Table Range	3 · Supplementary data · Table S1

CV and galvanostatic charge-discharge

Voltammetry Galvanostatic cycling

NiCo2O4 MHS working electrode · Electrode

Three-electrode cell; 3 M KOH electrolyte; Pt counter electrode; saturated calomel reference; current densities 1-30 A g-1

Geometry: slurry-coated nickel foam working electrode
Context: control active material in composite working electrode
Measurement source: 110 · 2.3. Electrochemical measurements · Fig. 5a,b,e,f

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
NiCo2O4 specific capacitance at 1 A g-1	approximately 725 F g-1 at 1 A g-1 from Fig. 5e	725 F g-1	visual estimate, roughly +/-25 F g-1	Visual Estimate Approximate	113 · Figure inspection · Fig. 5e
NiCo2O4 specific capacitance at 30 A g-1	approximately 475 F g-1 at 30 A g-1 from Fig. 5e	475 F g-1	visual estimate, roughly +/-25 F g-1	Visual Estimate Approximate	113 · Figure inspection · Fig. 5e
NiCo2O4 CV scan-rate series	5, 10, 20, 40, 60 and 80 mV s-1	—	—	Figure Axis Exact Reported	113 · Figure inspection · Fig. 5a

CV and galvanostatic charge-discharge

Voltammetry Galvanostatic cycling

(Ni0.33Co0.67)Se2 CHS working electrode · Electrode

Three-electrode cell; 3 M KOH electrolyte; Pt counter electrode; saturated calomel reference; current densities 1-30 A g-1

Geometry: slurry-coated nickel foam working electrode
Context: target active material in composite working electrode
Measurement source: 110 · 2.3. Electrochemical measurements · Fig. 5c,d,e,f

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Coulombic efficiency	nearly 100%	1 fraction	—	Text Approximate	5 · Supplementary data · Fig. S3
specific capacitance at 10 A g-1	726.6 F g-1 at 10 A g-1	726.6 F g-1	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 5e
specific capacitance at 12 A g-1	719.1 F g-1 at 12 A g-1	719.1 F g-1	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 5e
specific capacitance at 16 A g-1	697.5 F g-1 at 16 A g-1	697.5 F g-1	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 5e
specific capacitance at 1 A g-1Marked as a best value within this paper	827.9 F g-1 at 1 A g-1	827.9 F g-1	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 5e
specific capacitance at 20 A g-1	677.4 F g-1 at 20 A g-1	677.4 F g-1	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 5e
specific capacitance at 2 A g-1	804.3 F g-1 at 2 A g-1	804.3 F g-1	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 5e
specific capacitance at 30 A g-1	646.2 F g-1 at 30 A g-1	646.2 F g-1	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 5e
specific capacitance at 4 A g-1	775.3 F g-1 at 4 A g-1	775.3 F g-1	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 5e
specific capacitance at 6 A g-1	762.0 F g-1 at 6 A g-1	762 F g-1	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 5e
specific capacitance at 8 A g-1	743.9 F g-1 at 8 A g-1	743.9 F g-1	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 5e
(Ni0.33Co0.67)Se2 CV scan-rate series	5, 10, 20, 40, 60 and 80 mV s-1	—	—	Figure Axis Exact Reported	113 · Figure inspection · Fig. 5c
specific capacitance after 2000 cycles at 6 A g-1	865.8 F g-1 after 2000 cycles at 6 A g-1	865.8 F g-1	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 5f
capacitance retention from 1 to 30 A g-1	about 78.1%	0.781 fraction	—	Text Exact Reported	114 · 3. Results and discussion · Fig. 5e
CV redox-couple assignment	redox peaks assigned to Co2+/Co3+, Ni2+/Ni3+ and Co3+/Co4+ reactions	—	—	Text Qualitative	114 · 3. Results and discussion · Fig. 5a,c