Hierarchical Cu(OH)2@MnO2 core-shell nanorods array in situ

generated on three-dimensional copper foam for high-performance

supercapacitors

Huining Wang a,#, Guowen Yan a,#, Xueying Cao a, Ying Liu a, Yuxue Zhong a, Liang

Cui b,*, Jingquan Liu a,b,*

a College of Material Science and Engineering, Institute for Graphene Applied

Technology Innovation, Collaborative Innovation Centre for Marine Biomass Fibers,

Materials and Textiles of Shandong Province, Qingdao University, Qingdao, 266071,

Shandong, China

Email: jliu@qdu.edu.cn

b College of Material Science and Engineering, Linyi University, Linyi, 276000,

Shandong, China

Email: cuiliang@lyu.edu.cn

# Huining Wang and Guowen Yan contributed equally to this work.

Fig. S1. SEM images of (a, c) Cu(OH)2@MnO2/CF (20 mM), (b, d)

Cu(OH)2@MnO2/CF (40 mM) nanorods array at different magnifications.

Fig. S2. XPS survey spectrum of Cu(OH)2@MnO2/CF electrode.

Fig. S3. (a) CV curves and (b) GCD curves of the Cu(OH)2/CF electrode at various

scan rates and different current densities. (c) CV curves and (d) GCD curves of the

MnO2 powder electrode at various scan rates and different current densities.

Fig. S4. (a) CV curves and (b) GCD curves of the Cu(OH)2@MnO2 (20 mM)

electrode at various scan rates and different current densities. (c) CV curves and (d)

GCD curves of the Cu(OH)2@MnO2/CF (40 mM) electrode at various scan rates and

different current densities.

Fig. S5 (a) CV curves of the Cu(OH)2@MnO2/CF electrode at various scan rates. (b)

b-value calculated from the relationship between the peak currents and the scan rates

of the Cu(OH)2@MnO2/CF electrode. (c) Separation of the capacitive (shaded region)

and diffusion currents of the Cu(OH)2@MnO2/CF electrode at a scan rate of 20 mV s-

1. (d) Contribution ratio of the diffusion-controlled and capacitance-controlled charges

of the Cu(OH)2@MnO2/CF electrode at different scan rates.

Fig. S6 Cycling stability of the MnO2 powder electrode at a current density of 0.8 A g-

1.

Fig. S7 SEM images of the Cu(OH)2@MnO2/CF electrode (a) before and (b) after

cycling test. (c) TEM images and (d) HRTEM of the Cu(OH)2@MnO2/CF electrode

after cycling test.

Fig. S8 (a) XPS survey spectrum of Cu(OH)2@MnO2/CF electrode and high-

resolution XPS spectra for (b) Cu 2p, (c) Mn 2p and (d) O 1s of the

Cu(OH)2@MnO2/CF after cycling test.

Fig. S9 (a) CV curves and (b) GCD curves of the AC electrode at various scan rates

and different current densities.

Table S1. Comparison of the electrochemical properties of as-prepared

Cu(OH)2@MnO2/CF electrode with other MnO2-based electrode.

Electrodes Electrolyte Specific

capacitance

Capacitance retention Ref

Cu(OH)2@MnO2/CF 6 M KOH 283.45 F g-1

(0.8 A g-1)

85.17%

(5000 cycles)

This work

urchin-like MnO2 1 M Na2SO4 151.5 F g−1

(1 A g-1)

93.4%

(1000 cycles)

[1]

MnO2/CuO 1 M Na2SO4 167.2 F g-1

(0.3 A g-1)

88.6%

(5000 cycles)

[2]

CNT@NCT@MnO2 1 M Na2SO4 210 F g-1

(0.5A g-1)

90.2%

(1000 cycles)

[3]

MnO2/graphene 1 M KOH 110 F g-1

(1.75 A g-1)

/ [4]

MnO2 NP/graphene 30 wt% KOH 264 F g-1

(5 mV s-1)

73%

(6000 cycles)

[5]

Table S2. Comparison of the energy density and power density for the as-prepared

Cu(OH)2@MnO2/CF//AC asymmetric supercapacitors with other MnO2-based

asymmetric supercapacitors published in recent papers.

Asymmetric

Supercapacitors

Energy density

(Wh kg-1) max

Power density

(W kg-1)

Ref

Cu(OH)2@MnO2/CF//AC 18.36 750 This work

CNT@NCT@MnO2//CNT@NCT 13.3 90 [3]

MnO2//Bi2O3 11.3 352.6 [6]

α-MnO2@MWCNT//AC 17.8 400 [7]

GF@PPy@MnO2 13 1400 [8]

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