Effect of orientation on the reversible discharge capacity of electrodeposited Cu₂O coatings as lithium-ion battery anodes

Electrodeposited Cu₂O coatings with 111 out-of-plane orientation were found to have the lowest reversible discharge capacity as anodes for Li-ion cells. This is attributed to the low surface energy and the consequent high thermodynamic stability of the 111 crystal face of Cu₂O. In contrast, the 200 oriented coating has a higher reversible discharge capacity, owing to its polar nature and high surface energy. The highest reversible discharge capacity was observed for unoriented coatings, emphasizing the critical role played by grain boundaries in the conversion electrodes. The morphology of crystallites in the electrodes recovered after cycling is different in the three cases, suggesting that the nature of reversible chemical conversion is guided by physical attributes of the precursor Cu₂O crystallites.