carbon black hybrid material: A novel binary conductive additive for lithium-ion batteries

1082

CARBON 93 (2015) 1081– 1084

Boron-catalyzed graphitization of carbon fibers was conducted

c

School of Chemical and Environmental Engineering, North University of

in a boron-doped graphite crucible at 2000 °C, in which boron dif-

China, Taiyuan 030051, China

fused from the crucible to the carbon fibers to act as the catalyst.

d

The microstructures, boron contents and mechanical properties

University of Technology, Taiyuan 030024, China

Research Center of Materials Science and Technology, Taiyuan

of the resulting carbon fibers were characterized by Raman spectroscopy, scanning electron microscopy, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy and mechanical tests. Results indicate that boron has a significant impact on the fiber microstructure. Raman spectra indicate the presence of distortions in the graphitic layers. The tensile modulus of boron-doped carbon fibers obviously increases with boron content and the tensile strength is also higher than that of the original carbon fibers at boron concentrations between 0.58 and 0.68 at.%. [New Carbon Materials 2015, 30(2): 122–127]

Graphene oxide (GO) prepared by the Hummers method was hydrothermally reduced for 5 and 10 h to obtain 5-RGO and 10RGO, respectively. The GO and RGOs reacted with phenyl isocyanate to obtain three solution-processable functionalized graphenes (SPFGO, 5-SPFRGO and 10-SPFRGO), which were used as electron acceptors to prepare composite films with poly 3hexylthiophene (P3HT) as an electron donor in polymer solar cells. Results indicate that GO consists of about 3–5 layers, and the RGOs still have some oxygen-containing functional groups such as –COOH and C@O after the reduction. Functionalized

http://dx.doi.org/10.1016/j.carbon.2015.04.070

GOs have good dispersibility in dichlorobenzene and exhibit energy levels matching P3HT, indicating that they can be used

A graphene/carbon black hybrid material: A novel binary con-

as the electron acceptor materials of polymer solar cells. A5-

ductive additive for lithium-ion batteries

SPFRGO/P3HT composite film exhibits good compatibility, strong

Yong Lia, Xiao-hui Lub, Fang-yuan Sua,c, Yan-bing Hea, Bao-huaLia,

light absorption and obvious fluorescence quenching, suggesting

Quan-hong Yanga,b, Fei-yu Kanga

that 5-SPFRGO is an excellent electron acceptor material.

a

Shenzhen

Key

Laboratory

for

Graphene-based

Materials

and

Engineering Laboratory for Functionalized Carbon Materials, Graduate

[New Carbon Materials 2015, 30(2): 133–140] http://dx.doi.org/10.1016/j.carbon.2015.04.072

School at Shenzhen, Tsinghua University, Shenzhen 518055, China b

School of Chemical Engineering and Technology, Tianjin University,

Tianjin 300072, China

Nanoporous carbons from oxidized green needle coke for use in

c

high performance supercapacitors

Key Laboratory of Carbon Materials, Institute of Coal Chemistry,

Chinese Academy of Sciences, Taiyuan 030001, China A novel graphene(GN)/carbon black(CB) binary conductive

Jiu-zhou Wang, Li-qun Wang, Ming-ming Chen, Cheng-yang Wang, Cui Zhang, Fei He

additive has been developed, which is characterized by a unique

Key Laboratory for Green Chemical Technology of Ministry of Education,

microstructure and excellent performance for lithium ion batter-

School of Chemical Engineering and Technology, Tianjin University,

ies (LIBs). It was fabricated using a hydrothermal process, fol-

Tianjin 300072, China

lowed by heat treatment. The introduction of CB particles prevents GN from agglomerating and hence improves the elec-

Green needle coke was oxidized by a mixture of HNO3 and

tronic conductivity of the resulting additive. CB particles can also

H2SO4 (3:7 vol/vol) acids. The resultant oxidized coke was sepa-

enhance the Li+ ion diffusion, owing to a reduction of the GN frac-

rated into water dispersible and non-dispersible fractions, which

tion and an increase in electrolyte adsorption. Therefore, the rate

were then activated by KOH using the same KOH/coke weight

performance of the LIB is improved to some extent. Experimental

ratio to obtain two kinds of nanoporous carbons with different

data shows that the specific capacity of LiFePO4 containing 5 wt%

pore structures. The oxidized coke and the nanoporous carbons

of this binary conductive additive (after 900 °C treatment) is

were characterized by XPS, XRD, TEM, N2 adsorption and electro-

73 mAh/g at 10 °C, which is superior to that of LiFePO4 with

chemical tests. Results indicate that, at the same KOH/coke

10 wt% of CB (62 mAh/g). Compared with the latter, the former

ratios, the nanoporous carbons derived from the water-dis-

has a specific capacity increase of 25% based on the mass of the

persible oxidized coke have higher mass specific capacitances

whole electrode and shows superior cycle stability.

and capacitance retention ratios, and lower resistances than

[New Carbon Materials 2015, 30(2): 128–132]

those from the non-dispersible ones when used as an electric double layer capacitor electrode in 6 M KOH, but the former have

http://dx.doi.org/10.1016/j.carbon.2015.04.071

a lower volumetric specific capacitance than the latter. [New Carbon Materials 2015, 30(2): 141–149]

Structure and optical property of functionalized reduced gra-

http://dx.doi.org/10.1016/j.carbon.2015.04.073

phene oxides as electron acceptors in polymer solar cells La-qin Qua,b,c, Wei-jia Yanga,d, Ya-min Haoa,d, Yong-zhen Yanga,d, Xu-guang Liua,b a

Spontaneous reduction of palladium chloride on surface of carbon materials to produce electrochemical catalysts for ethanol

Key Laboratory of Interface Science and Engineering in Advanced

Materials, Ministry of Education, Taiyuan University of Technology,

oxidation Li-zhi Sun, Qing-feng Yi

Taiyuan 030024, China b

College of Chemistry and Chemical Engineering, Taiyuan University of

Technology, Taiyuan 030024, China

School of Chemistry and Chemical Engineering, Hunan University of Science and Technology, Xiangtan 411201, China