From graphite-clay composites to graphene electrode materials: In-situ electrochemical oxidation and functionalization

Journal Article · Fri Dec 15 04:00:00 EST 2017 · Materials Research Bulletin

DOI:https://doi.org/10.1016/J.MATERRESBULL.2017.01.025· OSTI ID:22730524

Chen, Kunfeng; Xue, Dongfeng

Highlights: • Graphene was synthesized by electrochemical exfoliation of graphite-clay rods with different clay:graphite ratios. • In-situ electrochemical oxidation and functionalization were used in the exfoliated process. • Graphene thin-film electrodes were constructed for supercapacitors and lithium ion batteries. • This work provided a value-added way that can transform the low-purity graphite resources to graphene electrode materials. - Abstract: The development of cost- and time-effective methods to synthesize graphene materials is very urgent in order to promote its large-scale application in electrochemical energy storage devices. Herein, graphene materials were synthesized by the electrochemical exfoliation (electrochemical oxidation) of graphite-clay rods with different clay:graphite ratios in aqueous solution and in short reaction time (1 h). The dual role of electrochemical oxidation reaction was presented: (1) the electrochemical oxidation reaction facilitates the exfoliation of pencil graphite leads and in-situ forms functional groups on graphene; (2) the electrochemical oxidation reaction enhances the Faradaic reaction in supercapacitor. The in-situ electrochemical oxidation and functionalization methods can transform low purity graphite to high-value graphene electrode materials for supercapacitors and lithium ion batteries. The specific capacitances of exfoliated graphene are 20-time larger than that of graphite-clay composites. This work provided a value-added way that can transform the low-purity graphite resources to high performance graphene electrode materials.

• OSTI ID: 22730524
• Journal Information: Materials Research Bulletin, Journal Name: Materials Research Bulletin Journal Issue: Part 3 Vol. 96; ISSN MRBUAC; ISSN 0025-5408
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AQUEOUS SOLUTIONS
CAPACITIVE ENERGY STORAGE EQUIPMENT
CLAYS
ELECTROCHEMISTRY
ELECTRODES
GRAPHENE
GRAPHITE
LITHIUM ION BATTERIES
MATERIALS
OXIDATION
OXIDES
SYNTHESIS
THIN FILMS