(378y) Cuprous Bromide: An Examination of High Halide Copper Electrodeposition and Its Application in a Flow Battery

Recent advances in an all-copper flow battery has created a renewed interest in copper electrodeposition from high concentration (>1M) halide electrolyte¹. This renewed interest is motivating further studies towards understanding high halide copper electrochemistry and its implications in various applications. The most apparent distinction between a high concentration halide copper electrolyte and a traditional copper sulphate electrolyte is that the high concentration halide electrolyte stabilizes the copper (I) oxidation state. There are limited reported studies in the literature of kinetics², diffusion^2,3, thermodynamics⁴, and morphology⁵ related to copper deposition from halide electrolytes. However, these studies are few and limited to the chloride chemistry. More work needs to be completed in other halides to fully understand the mechanistic nuances of these chemistries.

Since high bromide copper electrochemistry has been minimally studied, this work aims to advance our knowledge of high halide copper systems, in particular cuprous bromide. Various electroanalytical techniques were used to investigate the morphological and electrochemical differences of cuprous bromide and cupric sulphate. This presentation highlights the electrochemical and morphological differences and discusses the performance of an all-copper flow battery in a high concentration bromide electrolyte.

(1) Lloyd, D.; Magdalena, E.; Sanz, L.; Murtomäki, L.; Kontturi, K. Preparation of a Cost-Effective, Scalable and Energy Efficient All-Copper Redox Flow Battery. J. Power Sources 2015, 292, 87–94.
(2) Sanz, L.; Palma, J.; Garcia-Quismondo, E.; Anderson, M. The Effect of Chloride Ion Complexation on Reversibility and Redox Potential of the Cu(II)/Cu(I) Couple for Use in Redox Flow Batteries. J. Power Sources 2013, 224, 278–284.
(3) Ribeiro, A. C. F.; Esteso, M. A.; Lobo, V. M. M.; Valente, A. J. M.; Simões, S. M. N.; Sobral, A. J. F. N.; Burrows, H. D. Diffusion Coefficients of Copper Chloride in Aqueous Solutions at 298.15 K and 310.15 K. J. Chem. Eng. Data 2005, 50, 1986–1990.
(4) Zhao, H.; Chang, J.; Boika, A.; Bard, A. J. Electrochemistry of High Concentration Copper Chloride Complexes. Anal. Chem. 2013, 85, 7696–7703.
(5) Mackinnon, D. J.; Brannen, J. M.; McMillan, R. S. Factors Affecting the Structure of Copper Deposits Electrowon from Aqueous Chloride Electrolyte. J. Appl. Electrochem. 1985, 15, 649–658.