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Abstract: Phenolic-based carbon foams with controllable pore structure and high compressive strength were prepared by foaming of resin solution under the pressure of 4MPa and then carbonizing. Results showed that the average pore size of carbon foam ranging from 20 to 180nm can be controlled by changing the resin concentration. The nanometer pore structure resulted in significant improvement of compressive strength and thermal insulation properties of the carbon foams. Carbon foam with bulk density of 0.73g/cm3, average pore size of 20nm, compressive strength of 98.3MPa and thermal conductivity of 0.24W/mK was obtained. [Copyright &y& Elsevier]

Unusual sheets-like primary activated carbon particles interconnected into three-dimensional micrometer-level large pores were prepared from a novel biomass named willow catkins (WCs) by KOH chemical activation process and used as electrode materials for supercapacitors. The pore structures, surface area and chemical properties could be facilely adjusted by changing the activation temperature. When the activation temperature increased from 600 to 800 °C, the specific surface area of the porous carbon product increased remarkably while the contents of nitrogen and oxygen co-doped decreased, which significantly affected the electrochemical properties of the porous carbon-based supercapacitors. The activated carbons from 600 °C activation possesses despite moderate specific surface area (645 m 2 g −1 ), concentrated pore size distribution of 0.77 nm, but high nitrogen (2.51 wt.%) and oxygen (13.28 wt.%) contents, high graphitization degree as well as good electrical conductivity. The supercapacitors with the carbon electrode reached maximal specific capacitances of 340 F g −1 and high specific surface capacitance of 52.7 μF cm −2 at the current density of 0.1 A g −1 , good rate capability (231 F g −1 at 10 A g −1 ) and good cycling stability (92% capacitance retention over 3000 cycles). The favorable capacitive performances make the waste biomass WCs act as a new resource of carbonaceous materials for high performance supercapacitors. [ABSTRACT FROM AUTHOR]

Thermal management system is a key component to maintain the performance of lithium-ion batteries in electric vehicles. Cooling technology based on phase change materials with single-phase transition range has been proposed by many researchers but the temperature control of batteries is not ideal for high charge/discharge rates and cycle tests. Herein, we designed a novel phase change material consisting of paraffin with dual-phase transition ranges (around 34 °C and 48 °C), expanded graphite (thermal conductivity = 40 W/m K), and epoxy resin with a mass ratio of 5:2:3. This material was combined with graphite film (in-plane thermal conductivity of 1400 W/m K) to prepare a thermal management module. Graphite film and expanded graphite form an excellent heat conduction structure. Epoxy resin endows this composite with satisfactory mechanical properties, even at 70 °C. The paraffin provides a double buffer effect that minimizes the temperature increase of the batteries and the temperature differences between the batteries in the pack due to the broad phase transition range. As a result, the maximum temperature of the batteries is 33 °C and the maximum temperature difference between the batteries is only 1.4 °C, even at the highest 4C discharge rate. In addition, the maximum temperature of the batteries is only 44.8 °C after six extreme cycles. • The chosen paraffin has a double buffer effect on temperature rising of batteries. • Mechanical properties of this phase change material are prominent, even at 70 °C. • The maximum temperature in battery pack is 33 °C at the highest 4C discharge rate. • The maximum temperature difference is 2.8 °C under all charge/discharge rates. • Highest temperature of the batteries is only 44.8 °C in the extreme cycle test. [ABSTRACT FROM AUTHOR]

Abstract Micron-grade carbon microtubes (CMTs) decorated with layered Ni-Co sulphides of several hundred nanometers and accompanied by Ni-Co sulphides nanoparticles composite structures have been fabricated by facile hydrothermal synthesis method, using willow catkins derived CMTs as carbon scaffolds and ethylene glycol mixture solution containing nickel acetate, cobalt acetate and thiourea as precursors for Ni-Co sulphides. The controllable Ni/Co molar ratios of Ni-Co sulphides can be altered by adjusting the ratio of nickel acetate and cobalt acetate in mixture solution. The electrochemical performance of CMTs/Ni-Co sulphides can be greatly affected by CMTs conductivity, Ni-Co sulphides deposition amounts and crystalline structures. Nevertheless, the hollow tubular structure of CMTs/Ni-Co sulphides composites can provide fast transport channels for ions diffusion while the great conductivity of CMTs scaffolds may facilitate the access of electrons transportation. Owing to this unique structure, the CMTs-1000/Ni 2 CoS 4 composite exhibits an optimal pseudocapacitance (1210 F g−1 at 0.5 A g−1), good rate capability of 83.8% (1014 F g−1 at 10 A g−1) and good cycling durability of 95% retention of the initial value over 3000 charge-discharge cycles, well above the value of pure Ni 2 CoS 4 that is merely 66.1% (1210 F g−1 at 0.5 A g−1 and 800 F g−1 at 10 A g−1) with inferior cycling durability of 78%. Besides, a maximum energy density of 28.1 Wh kg−1 for the CMTs-1000/Ni 2 CoS 4 //AC asymmetric supercapacitor (ASC) device can be achieved at power density of 753 W kg−1, and the energy density can still maintain 17.7 Wh kg−1 even at high power density of 17.2 kW kg−1. [ABSTRACT FROM AUTHOR]