Magnetic field intensified electrodeposition of low-concentration copper ions in aqueous solution

A large amount of low-concentration copper ion solution is generated during the recycling process of lithium-ion batteries. Low efficiency and poor selectivity for electrodeposition recovery of low-concentration copper ion solution due to slow ion migration rate. To increase the ion transfer rate of the diffusion layer, the low-concentration copper ion solution was pre-magnetized or in-situ magnetized for electrodeposition. Results indicated that the pre-magnetized electrolyte or magnetic field assisted-electrodeposition process could change the hydrogen bond structure, increase the solution viscosity, reduce the interface transfer resistance (Rct) and the transfer coefficient of copper ions in the diffusion layer, while reduce the radius of hydrated particles, the symmetry of the hydrated ion structure, and the activation energy of the reaction. As a result, the electrolysis efficiency increased from 22.1 to 32.3% for 0.01 mol/L CuSO4 solution, and from 92.3 to 98.1% for 0.1 mol/L CuSO4 solution after pre-magnetization.