Stabilizing Effect of Polycrystalline Diamond on Anodic Electrodes for Li Ion Batteries

This study addresses the issue of rapid degradation and limited efficiency of lithium-ion batteries (LIBs), crucial devices for energy storage due to their high energy density, low weight, and low self-discharge rate. In this context. The use of ultrananocrystalline diamond (UNCD) films and unique electrically conductive grain boundary nitrogen-incorporated ultrananocrystalline diamond (N-UNCD) on superficies de Natural Graphite (NG)/cooper (Cu) anodes is investigated to enhance the stability of capacity energy vs. charge/discharge cycles, safety and performance of LIBs with the new anodes.<br/>The primary objective of this research is to evaluate the stabilizing effect of UNCD and N-UNCD coatings on NG/Cu anodes in half-cell lithium-ion configurations. The study aims to determine how the UNCD and N-UNCD coating improve the performance of half-cells considering specific capacity, coulombic efficiency, and inherent electrochemical processes such as solid electrolyte interface (SEI) formation and charge transfer.<br/>Half-cell LIBs were assembled with different anode configurations, namely: NG/Cu, currently used in commercial LIBs, UNCD/NG/Cu, and N-UNCD/NG/Cu, alongside a metallic lithium reference electrode. Characterization of these cells involved techniques such as lithiation and delithiation cycles, specific capacity measurements, coulombic efficiency assessments, and electrochemical impedance spectroscopy (EIS). Additionally, distribution of relaxation times (DRT) and equivalent circuit models (ECM) were employed to analyze the electrochemical processes of the studied half-cells and compare their resistances to identify correlations indicative of the effect provided by the UNCD and N-UNCD coatings on the anode of a half-cell LIB.<br/>The use of UNCD and N-UNCD coatings on graphite anodes significantly contributes to improve the stability and performance of LIBs’ half-cells. The findings suggest that such coatings could serve as a viable solution to extend the lifespan, safety and efficiency of LIBs, crucial for the advancement of sustainable energy technologies.