▎ 摘　　要

In the present study, we designed and prepared multilayer NiO@Co3O4 hollow spheres decorated with graphene quantum dots (NiO@Co3O4@GQDs) through a rational solvothermal treatment. The decoration of the GQDs endowed the hybrid structure with excellent electrochemical behaviors in lithium-ion batteries (LIBs) and supercapacitors (SCs). The core-shell NiO@Co3O4 hollow structure was designed based on the stepwise lithium storage mechanism (first in the Co3O4 shell and then in the NiO core). The carboxyl-functionalized GQDs led to reduced interfacial resistance and increased surface area for electrochemical reactions. The high polarity of the carboxyl functionalized GQDs also showed a strong affinity to the Li+ in LIBs and K+/OH- in SCs. As an anode for LIBs, it demonstrated a large reversible capacity of 1158 mA h g(-1) (NiO@Co3O4 contribution: approximate to 1327 mA h g(-1)) after 250 cycles at 0.1 A g(-1). As a SC cathode, it held an impressive high specific capacitance of 1361 F g(-1) (748.5 C g(-1)) at 1 A g(-1), and retained 76.4% capacitance after 3000 cycles. Moreover, the assembled all-solid-state asymmetric supercapacitors (ASCs) (NiO@Co3O4@GQDs//AC) could deliver an energy density of 38.44 W h kg(-1) and a superior cyclability (84.3% retention after 10000 cycles).