Enhancing the Electrochemical Performance of CPO-27-Co Through Microwave-Assisted Nanosizing

This study investigates the electrochemical performance of CPO-27-Co as a Li-ion battery electrode, focusing on the effects of its porous structure and nanoscale size reduction. Nanosizing enhances the external surface area at the expense of intrinsic crystal porosity. CPO-27-Co was synthesized using solvothermal and microwave-assisted methods to compare the impact of crystallinity, surface area and nanosizing in the electrochemical performance. Characterization by FTIR, PXRD and TEM confirms the successful formation of crystalline phases, with the microwave method producing either micro or nanoscale particles in a significantly shorter time. Nitrogen adsorption-desorption measurements reveal that textural properties are preserved in large particles produced by microwave but decrease in nanoscale samples due to the loss of internal porosity. Electrochemical analysis shows that all materials exhibit lithium insertion activity, with the nanoscale material CPO-27-Co MW 2 achieving nearly the theoretical capacity ca. 135 mAh/g. This result highlights that particle size reduction and structural disorder, rather than high crystallinity or pore accessibility, are the key factor in optimizing the electrochemical performance of CPO-27-Co. These findings pave the way for further exploration of other members of the CPO-27 family, particularly those containing more sustainable metals, and provide insights into the general behavior of metal-organic frameworks in energy storage applications.