**Acknowledgements**

**Figure 6.** Ragone plot of Mn3

**Aqueous electrolyte/ concentration**

H2 SO4

H2 SO4

H2 SO4

Na<sup>2</sup> SO4

Li2 SO4

Na<sup>2</sup> SO4

from [35] with permission from RSC).

62 Supercapacitors - Theoretical and Practical Solutions

/0.5 M RuO2

/1 M RuO2

KOH/2 M NiCo<sup>2</sup>

NaOH/1 M Fe2

KOH/1 M Ni(OH)<sup>2</sup>

KOH/6 M Iron nanosheets/

/1 M CNT/V<sup>2</sup>

graphene

MnO2 /C

O5 nanocomposite//

/1 M Graphene-

 (PO4 )2

mesoporous PANI



510 133 1 [37]

570 10.62 1 [21]

720 140 1.2 [41]

– 16 1.6 [44]

**Electrode material Cs (F/g) E (W h kg−1) Potential window (V) Ref**

KOH/6 M Graphene 303 6.5 1 [38]

KCl/3 M Ni (OH)<sup>2</sup> 718 – 0.5 [42]

/1 M Activated carbon 180 – 2.2 [31]

/1 M Hydrous RuO2 56.66 18.77 1.6 [45]

**Table 3.** Some important aqueous-based electrolyte supercapacitors and their performance.


O4 1647.6 38 0.41 [39]

O3 178 – 0.5 [43]

/graphene 160 48 1.5 [40]

This work was supported by National Natural Science Foundation of China (Project No. 51505209) and Shenzhen Science and Technology Innovation Committee (Projects No. JCYJ20170412154426330). Fei Wang is also supported by Guangdong Natural Science Funds (Project Nos. 2015A030313812 and 2016A030306042). This chapter is partly supported by the State Key Laboratories of Transducer Technology, Shanghai, China.

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