The use of lithium-ion battery has developed a lot of interest as a result of their attractive features in energy delivery which has led to researchers providing ways whereby their performance and capacity could be increased.
In order to increase the efficiency and capacity of a lithium-ion battery, researchers have discovered that when copper oxide is used as an anode at certain morphologies and compositions, positive results such as increase in energy density and life cycle of a lithium-ion battery could be achieved.
It should be noted that morphologies of current collectors play a major role in determining the electrochemical activities of lithium-ion batteries. With this, various fabrication methods for development of current collectors have also been carried out and certain improvement in performance of lithium-ion batteries has been achieved. However, the joints effects of material composition and surface structure of current collectors in electrochemical performance of lithium-ion batteries have not been provided.
A comprehensive study on the combined effects of surface structure and material composition of current collectors in view of lithium-ion battery electrochemical performance was provided by team of researchers led by Professor Wei Yan from School of Mechanical and Automotive Engineering at South China University of Technology.
The research work which is now published in Electrochimica Acta involved preparation of composite current collector of copper oxide layers from formed array-pattern porous blind holes on thin copper plates via chemical etching method while mesocarbon microbead graphite powders were used as anode material.
They also investigated the electrochemical performances of the developed porous composite current collectors and that of its complanate structures which didn’t involve an ultraviolet exposure machine and a developer solution compared to the former, followed by electrochemical testing and characterization of the material with the aid of CR2032 coin half-cell test, voltammetry test, scanning electron microscopy and electrochemical impedance spectroscopy.
At first, they discovered a higher electrical conductivity in the porous composite current collector compared to the complanate ones as a result of contact increase between the electrode material and current collector. The oatmeal-like structure of the copper oxide layer on the array-pattern blind holes played the major role in this.
Also, the discharge capacity of the porous composite current collector at a constant current delivery was found to be 383.9m Ah g-1 compared to the complanate ones with value of 309.6m Ah g-1. After certain rate cycles, the discharge capacity was also higher in the former compared to the latter.
Outcomes from the discharge-charge voltage profiles of lithium-ion battery after the 1st, 5th, 15th and 20th cycle indicated a gradual increase in columbic efficiency and a minute loss in discharge-charge capacity for the porous current collectors compared to the complanate current collectors.
A higher cycling stability was also observed for the porous current collector compared to the complanate ones. These results were also attributed to the oatmeal-like morphologies of the copper oxide layers.
Results from electrochemical impedance spectroscopy also indicated lesser alternating current impedance and total resistance of lithium-ion batteries with the porous composite collector compared to the complanate ones. As a result of this, electrochemical performance of the lithium-ion battery was enhanced.
The authors were able to provide a significant improvement on the efficiency and capacity of lithium-ion batteries with the use of the developed composite current collector of copper oxide layers with an array-pattern porous structure on thin copper plates.
Yuan, W., Luo, J., Yan, Z., Tan, Z., Tang, Y. High-Performance CuO/Cu Composite Current Collectors with Array-Pattern Porous Structures for Lithium-Ion Batteries, Electrochimica Acta 226 (2017) 89–97.Go To Electrochimica Acta