metals Article Selective Separation and Recovery of Li from Spent LiFePO4 Cathode Materials by Oxidation Roasting Followed by Low-Acid Pressure Leaching Zaoming Chen 1,2, Changquan Shen 1, Fupeng Liu 1,2,* and Jinliang Wang 1,2 1 Faculty of Materials Metallurgy and Chemistry, Jiangxi University...