Electronic Supplementary Information

One-pot synthesis of nickel-cobalt hydroxyfluorides nanowires

with ultrahigh energy density for an asymmetric supercapacitor

Jian-Fang Zhang,a Yan Wang,a,b,* Xia Shu,a Cui-Ping Yu,a Ming-Feng Xiaoa, Jie-Wu

Cui,a Yong-Qiang Qin,a Hong-Mei Zheng,a Yong Zhang,a Dong Chen,c Pulickel M.

Ajayan,b Yu-Cheng Wua, d, *

aSchool of Materials Science and Engineering, Hefei University of Technology, Hefei

230009, China

bDepartment of Material Science and Nanoengineering, Rice University, Houston,

Texas 77005, USA

cSchool of Instrument Science and Opto-electronics Engineering, Hefei University of

Technology, Hefei 230009, China

dKey Laboratory of Advanced Functional Materials and Devices of Anhui Province,

Hefei 230009, China.

*Corresponding authors

Email: stone@hfut.edu.cn (Y. Wang); ycwu@hfut.edu.cn (Y. C. Wu)

Fig. S1 EDS spectra of (a) Ni-HF, (b) Co-HF and (c) NiCo-HF

Fig. S2 XPS of NiCo-HF: (a) Survey, (b) Co 2p, (c) Ni 2p and (d) F 1s spectrum

Fig. S3 Nitrogen adsorption-desorption isotherm and the corresponding pore-size distribution curves of (a,b) Ni-HF, (c,d) Co-HF and (e,f) NiCo-HF

Fig. S4 Nitrogen adsorption-desorption isotherm and the corresponding pore-size distribution curves of NiCo-HF prepared at different temperatures of (a,b) 120, (c,d)

160, (e,f) 180°C

Fig. S5 EDS spectra of NiCo-HF prepared at different temperatures of (a,b) 120, (c,d) 160, (e,f) 180°C

Fig. S6 CV curves of (a) Ni-HF electrode, (b) Co-HF electrode at scan rates range from 2 to 100 mV s-1, GCD curves of (c) Ni-HF electrode, (d) Co-HF electrode at

current densities range from 1 to 20 A g-1.

Fig. S7 CV curves of NiCo-HF electrodes prepared at different temperatures of (a) 120, (b) 160, (c) 180 ℃; (d) Compared CV curves of different NiCo-HF electrodes at a scan rate of 50 mV s-1.

Fig. S8 Cycling performance of the NiCo-HF electrode at a scan rate of 20 mVs-1 for 10000 cycles, the inset shows the CV curves after different cycles

Fig. S9 GCD curves of NiCo-HF//AC asymmetric supercapacitor for the first and last 10 cycles during the stability test for 10000 cycles

Fig. S10 Optical photograph of 3 white and blue colored LEDs lit by two charged supercapacitors connected in series for 5 min.

Table S1. Comparison of the energy density and power density of NiCo-HF//AC asymmetric supercapacitor with other reports in the literatures.

Materials Energy density (Wh kg-1)

Power density(W kg-1) Ref.

NiCo-HF//AC 86.3 379.4 This work

CoS@eRG//AC 29 800 S1NiCo2S4@Co(OH)2//AC 35.89 400 S2

NiCo2S4//AC 35.6 819.5 S3

Nickel cobalt hydroxide nanoflowers 19.4 80.5 S4

Cobalt-manganese layered double hydroxide 4.4 2500 S5

MnO2/graphene 10.7 500 S6Ni3S2@-NiS//AC 55.1 925.9 S7

MnMoO4·nH2O//AC 31.6 935 S8

graphene@Mn3O4 nanosheets 50 64000 S9

NiFe2O4 nanocones forest 54.9 300 S10

References

[S1] Shi JH, Li XC, He GH et al. Electrodeposition of high-capacitance 3D CoS/graphene nanosheets on nickel foam for high-performance aqueous asymmetric supercapacitors. J. Mater. Chem. A 2015;3:20619–26.

[S2] Li R, Wang SL, Huang ZC et al. NiCo2S4@Co(OH)2 core-shell nanotube arrays in situ grown on Ni foam for high performances asymmetric supercapacitors. J. Power Sources 2016;312:156–64.

[S3] Wen YX, Peng SL,Wang ZL et al. Facile synthesis of ultrathin NiCo2S4

nano-petals inspired by blooming buds for high-performance supercapacitors. J. Mater. Chem. A 2017;5:7144–52.

[S4] Tang YF, Liu YY, Yu SX et al. Template-free hydrothermal synthesis of nickel cobalt hydroxide nanoflowers with high performance for asymmetric supercapacitor. Electrochim. Acta 2015;161:279–89.

[S5] Jagadale AD, Guan GQ, Li XM et al. Ultrathin nanoflakes of cobalt-manganese layered double hydroxide with high reversibility for asymmetric supercapacitor. J. Power Sources 2016;306:526–34.

[S6] Li ZM, An YF, Hu ZA et al. Preparation of a two-dimensional flexible MnO2/graphene thin film and its application in a supercapacitor. J. Mater. Chem. A 2016;4:10618–26.

[S7] Li W, Wang SL, Xin LP et al. Single-crystal -NiS nanorod arrays with a hollow structured Ni3S2 framework for supercapacitor applications J. Mater. Chem. A 2016;4:7700–9.

[S8] Mu XM, Zhang YX, Wang H et al. A high energy density asymmetric supercapacitor from ultrathin manganese molybdate nanosheets. Electrochim. Acta 2016;211:217–24.

[S9] Liao QY, Li SY, Cui H et al. Vertically-aligned graphene@Mn3O4

nanosheets for a high-performance flexible all-solid-state aymmetric supercapacitor. J. Mater. Chem. A 2016;4:8830–6.

[S10] Javed MS, Zhang CL, Chen L et al. Hierarchical mesoporous NiFe2O4

nanocone forest directly growing on carbon textile for high performance flexible supercapacitors. J. Mater. Chem. A 2016;4:8851–9.