Electrochemical activity and high ionic conductivity of lithium copper pyroborate Li6CuB4O10 F. Strauss, G. Rousse, D. Alves Dalla Corte, M. Ben Hassine, M. Saubanere, M. Tang, H. Vezin, M. Courty, R. Dominko, J-M. Tarascon Physical Chemistry Chemical Physics, 2016