Electrochemistry Application — 3D self-branched zinc-cobalt Oxide@N-doped carbon hollow nanowall arrays for high-performance asymmetric supercapacitors and oxygen electrocatalysis

6 measurement groups · 36 results

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

Quasi-solid-state asymmetric supercapacitor CV, charge/discharge, cycling, bending and Ragone analysis

Voltammetry

ZnCo2O4@NC//Fe3O4@r-GO ASC device · Electrode

ZnCo2O4@NC/CTs cathode, Fe3O4@r-GO/CTs anode and PVA-KOH gel electrolyte in 0-2.0 V voltage window.

Temperature: 298
Geometry: flexible all-solid-state ASC, about 1.0 mm total thickness
Context: application device with target MOF-derived cathode
Measurement source: 658 · 3. Results and discussion · Fig. 4

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
ASC areal capacitance at 20 mA cm^-2	400.2 mF cm^-2	0.4002 F cm^-2	—	Text Exact Reported	659 · 3. Results and discussion · Fig. S17c-d
ASC areal capacitance at 4 mA cm^-2Marked as a best value within this paper	545.8 mF cm^-2	0.5458 F cm^-2	—	Text Exact Reported	658 · 3. Results and discussion · Fig. S17c-d
maximum ASC areal energy densityMarked as a best value within this paper	0.278 mWh cm^-2	0.278 mWh cm^-2	—	Text Exact Reported	653 · Abstract
ASC areal power density at maximum areal energy density	4.0 mW cm^-2	4 mW cm^-2	—	Text Rounded Reported	654 · Introduction summary
ASC retention after 1000 bending cycles at 135 degrees	87.12%	87.12 %	—	Text Exact Reported	659 · 3. Results and discussion · Fig. S18a
ASC retention after 2000 bent-condition cycles	89.71%	89.71 %	—	Text Exact Reported	659 · 3. Results and discussion · Fig. S18b
ASC cycling capacitance retention	85.89% after 6000 cycles at 15 mA cm^-2	85.89 %	—	Caption Exact Reported	659 · Fig. 4 caption · Fig. 4f
ASC capacitance retention from 4 to 20 mA cm^-2	73.3%	73.3 %	—	Text Exact Reported	659 · 3. Results and discussion · Fig. S17c-d
ASC volumetric energy density at high power	1.70 mWh cm^-3 at 166.7 mW cm^-3	1.7 mWh cm^-3	—	Text Exact Reported	659 · 3. Results and discussion · Fig. 4h
maximum ASC volumetric energy densityMarked as a best value within this paper	2.32 mWh cm^-3 at 33.3 mW cm^-3	2.32 mWh cm^-3	—	Text Exact Reported	659 · 3. Results and discussion · Fig. 4h
stable ASC voltage windowMarked as a best value within this paper	up to 2.0 V	2 V	—	Text Rounded Reported	658 · 3. Results and discussion · Fig. S17a-b; Fig. 4d-e

ASC mass-balancing calculation

ZnCo2O4@NC//Fe3O4@r-GO ASC device · Electrode

Positive-to-negative electrode mass ratio balanced using capacitance and voltage-window formula in SI.

Geometry: ZnCo2O4@NC//Fe3O4@r-GO ASC
Context: application device
Measurement source: Part 2 Calculations

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
optimal positive-to-negative electrode mass ratio	0.862	0.862 dimensionless	—	Text Exact Reported	Part 2 Calculations

OER LSV, Tafel, EIS, Cdl and chrono-stability testing

Impedance spectroscopy Voltammetry Tafel and polarisation analysis

3D self-branched ZnCo2O4@NC/CTs · Electrode

Three-electrode OER tests in 1.0 M KOH, pH about 13.8, N2 purged 30 min; Pt wire counter, Ag/AgCl reference, potentials calibrated to RHE.

Temperature: 298
Atmosphere: N2-purged electrolyte
Geometry: binder-free working electrode, about 1.0 x 1.0 cm^-2
Context: target compared with bare CTs, ZnCo2O4/CTs and Co3O4@NC/CTs
Measurement source: 655 · 2.5. Electrochemical characterization · Fig. 5

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
ZnCo2O4@NC/CTs double-layer capacitanceMarked as a best value within this paper	206.9 mF cm^-2	206.9 mF cm^-2	—	SI Table Exact Reported	SI p.30 · Part 4 Tables · Table S2
OER current density at 1.65 V vs RHEMarked as a best value within this paper	101 mA cm^-2	101 mA cm^-2	—	Text Rounded Reported	660 · 3. Results and discussion · Fig. 5a
OER durability duration	over 45 h; polarization after 46 h shows negligible degradation	46 h	—	Text Rounded Reported	661 · 3. Results and discussion · Fig. 5f inset
ZnCo2O4@NC/CTs OER onset potentialMarked as a best value within this paper	~1.38 V vs RHE	1.38 V vs RHE	~	Text Approximate	660 · 3. Results and discussion · Fig. 5a
ZnCo2O4@NC/CTs overpotential at 10 mA cm^-2, 10 mV s^-1 scan	379.6 mV	0.3796 V	—	Text Exact Reported	661 · 3. Results and discussion · Fig. 5b
ZnCo2O4@NC/CTs overpotential at 10 mA cm^-2, 50 mV s^-1 scanMarked as a best value within this paper	196.4 mV	0.1964 V	—	Text Exact Reported	661 · 3. Results and discussion · Fig. 5b
control overpotentials at 10 mA cm^-2, 10 mV s^-1 scan	ZnCo2O4/CTs 510.3 mV; Co3O4@NC/CTs 555.2 mV; CTs 753.2 mV	—	—	Calculated From Reported Rounded Reported	661 · 3. Results and discussion · Fig. 5b
ZnCo2O4@NC/CTs OER charge transfer resistanceMarked as a best value within this paper	6.5 ohm	6.5 ohm	—	Text Exact Reported	661 · 3. Results and discussion · Fig. 5d
OER potential decrease during continuous polarisation	less than 4% after 40 h	4 %	<	Text Approximate	661 · 3. Results and discussion · Fig. 5f
ZnCo2O4@NC/CTs Tafel slopeMarked as a best value within this paper	61.3 mV dec^-1	61.3 mV dec^-1	—	Text Exact Reported	661 · 3. Results and discussion · Fig. 5c

Supplementary OER performance comparison table

3D self-branched ZnCo2O4@NC/CTs · Electrode

Table S2 reports substrate, mass loading, electrolyte, Cdl, potential at 10 mA cm^-2 and Tafel slope for ZnCo2O4@NC NWAs and literature catalysts.

Geometry: binder-free arrays on carbon textiles
Context: target MOF-derived OER electrode
Measurement source: SI p.30 · Part 4 Tables · Table S2

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Table S2 ZnCo2O4@NC NWA mass loading	1.12 mg cm^-2	1.12 mg cm^-2	—	SI Table Exact Reported	SI p.30 · Part 4 Tables · Table S2
Table S2 OER potential at 10 mA cm^-2Marked as a best value within this paper	1.379 V vs RHE at 10 mA cm^-2	1.379 V vs RHE	—	SI Table Exact Reported	SI p.30 · Part 4 Tables · Table S2

Supplementary comparison table of three-electrode areal/specific capacity

3D self-branched ZnCo2O4@NC/CTs · Electrode

Table S1 compares ZnCo2O4@NC nanowall arrays on carbon textiles in 2.0 M KOH against reported battery-type electrode materials.

Geometry: three-electrode system
Context: target MOF-derived electrode
Measurement source: SI p.28-SI p.29 · Part 4 Tables · Table S1

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
Table S1 areal capacity at 0.5 mA cm^-2Marked as a best value within this paper	2.278 F cm^-2 at 0.5 mA cm^-2	2.278 F cm^-2	—	SI Table Exact Reported	SI p.28 · Part 4 Tables · Table S1
Table S1 areal capacity at 64 mA cm^-2	1.676 F cm^-2 at 64 mA cm^-2	1.676 F cm^-2	—	SI Table Exact Reported	SI p.28 · Part 4 Tables · Table S1
Table S1 specific capacity at 0.5 mA cm^-2Marked as a best value within this paper	2034.02 F g^-1 at 0.5 mA cm^-2	2034.02 F g^-1	—	SI Table Exact Reported	SI p.28 · Part 4 Tables · Table S1
Table S1 specific capacity at 64 mA cm^-2	1496.62 F g^-1 at 64 mA cm^-2	1496.62 F g^-1	—	SI Table Exact Reported	SI p.28 · Part 4 Tables · Table S1

Three-electrode supercapacitor CV, galvanostatic charge/discharge and EIS

Impedance spectroscopy Voltammetry Galvanostatic cycling

3D self-branched ZnCo2O4@NC/CTs · Electrode

ZnCo2O4@NC/CTs, ZnCo2O4/CTs, Co3O4@NC/CTs and CTs tested in KOH aqueous electrolyte with Pt counter and Ag/AgCl reference; potential window 0-0.7 V vs Ag/AgCl for positive electrode.

Temperature: 298
Geometry: about 1.0 x 1.0 cm^-2 working area
Context: target compared with bare CTs, ZnCo2O4/CTs and Co3O4@NC/CTs controls
Measurement source: 655 · 2.5. Electrochemical characterization · Fig. S12-S14

Property	Reported value	Normalised value	Uncertainty	Origin and quality	Source
b value at oxidation peak	0.806	0.806 dimensionless	—	Text Exact Reported	658 · 3. Results and discussion · Fig. S12e
b value at reduction peak	0.846	0.846 dimensionless	—	Text Exact Reported	658 · 3. Results and discussion · Fig. S12e
specific capacitance at 2 mA cm^-2Marked as a best value within this paper	~2003.80 F g^-1	2003.8 F g^-1	~	Text Approximate	658 · 3. Results and discussion · Fig. S14
areal capacitance at 2 mA cm^-2Marked as a best value within this paper	~2.244 F cm^-2	2.244 F cm^-2	~	Text Approximate	658 · 3. Results and discussion · Fig. S12g
areal capacitance at 64 mA cm^-2	1.676 F cm^-2	1.676 F cm^-2	—	Text Rounded Reported	658 · 3. Results and discussion · Fig. S12g
single-electrode cycling capacitance retention	~99.37% after 10000 cycles at 32 mA cm^-2	99.37 %	~	Text Approximate	658 · 3. Results and discussion · Fig. S12h
ZnCo2O4@NC/CTs IR dropMarked as a best value within this paper	only 9 mV	0.009 V	—	Text Rounded Reported	657 · 3. Results and discussion · Fig. S12b
single-electrode rate capacitance retention	~73.6%	73.6 %	~	Text Approximate	658 · 3. Results and discussion · Fig. S12g