Supplementary Information

Fig. S1. The elements distribution sum spectra and corresponding EDS mapping of the obtained

samples.

Fig. S2. The zeta potentials of Graphene/CoAl LDH and CoAl LDH in different pH.

Fig. S3. The possible schematic of the interaction between the different types Graphene/CoAl LDH

and OH- from alkaline electrolyte. (a1) pure RGO, (a2) appropriate CoAl LDH on RGO, (a3) excess

of CoAl LDH on RGO, (b1) GO, (b2) appropriate CoAl LDH on GO, (b3) excess CoAl LDH on GO.

Fig. S4. The possible schematic of the increased specific capacitance of Graphene/CoAl LDH (a)

before and (b) after 20000 cycling.

Fig. S5. (a) The Coulombic efficiency of Graphene/CoAl LDH, Graphene/CoS, Graphene/CoOOH,

Graphene/Co-S and Graphene/CoP., (b) the Coulombic efficiency of Graphene/CoAl LDH before and

after cycling.

Fig. S6. The structure model of the obtained samples.