Search results

The purpose of this paper is to show how to obtain a supercapacitor with high specific power (P) and high specific energy (E_p) simultaneously.

The carbon aerogels are obtained by ambient pressure drying method instead of supercritical drying method and carbon aerogels/Ni(OH)₂ composites are prepared by in situ polymerisation. A series of asymmetric supercapacitors based on carbon aerogels/Ni(OH)₂ composites as positive electrode and activated carbon as negative electrode, respectively, are assembled. The electrochemical performances of carbon aerogels/Ni(OH)₂ composites and supercapacitors are studied.

The results show that the specific capacitance (C_P) of carbon aerogels/Ni(OH)₂ composites is 584 F/m². The working potential of supercapacitors could be increased to 1.6V. When the mass ratio of carbon aerogels and Ni(OH)₂ is 3:7, the mass ratio of positive electrode and negative electrode is 1:1, the E_P and P of the supercapacitor is higher than 10.5 Wh/kg and 578 W/kg, respectively, when the current varies from 50 mA to 100 mA and the attenuation ratio of C_P is only 8.3 per cent after 10,000 cycles at 100 mA.

The supercapacitors can be used in the field of automobile engineering and can solve the problems of energy shortage and environmental pollutions.

The supercapacitor based on carbon aerogels/Ni(OH)₂ composites as positive electrode and activated carbon as negative electrode is novel and the synthetic properties of the supercapacitor are excellent.

The purpose of this paper is to examine the significance of the direct and indirect effects (through country and firm’s specific advantages) of government policies for export promotion (GPEP) on the export performance of small and medium-size enterprise (SME) Cocoa exporters in Cameroon.

To test the proposed model, data were obtained through self-administered questionnaires using snowball sampling technique to 101 SME Cocoa exporters. This was analyzed using structural equation modeling (SEM) techniques to examine both the direct and indirect effects of GPEP on the export performance of SME Cocoa exporters in the South and Centre Regions of Cameroon.

The findings suggest that GPEP had both direct and indirect effects on the export performance of SME Cocoa exporters. Direct effect was on the usage of GPEP which reduces operating cost and increase performance. The indirect effects were through the provision of country and firms specific advantages. However, the only significant path was through the provision of export marketing information.

The research is limited to one country, one sector, and two regions and does not take into consideration other factors that may influence the effect of GPEP, country, and firms specific advantages on export performance. Moreover, the non-significant paths should be interpreted with caution and further testing required in a different context.

Empirical findings are relevant for the government and SME Cocoa exporters. It informs the government about the effectiveness of GPEP and the need to disseminate marketing information using every possible medium best understood by the SMEs. It suggests an opportunity for engagement of both SMEs and government authorities in accessing the outcome of GPEP which will increase transparency, awareness, usage, and export performance.

The research has successfully developed and tested a model for analyzing the direct and indirect effects of GPEP on export performance based on the resource-based view and SEM in a context where there is a call for more empirical and theoretical work on export performance due to limited studies. The framework reveals positive effects of GPEP, country, and firms’ specific advantages as determinants of export performance.