New qualitative colour reaction for the identification of copper(I) compounds and complexes

Multifunctional Catalyst CuS for Nonaqueous Rechargeable Lithium–Oxygen Batteries

“…Moreover, the solubility of CuS in the electrolyte was also confirmed with the EDS mapping images of Cu element on anode Li foil after discharge/charge for 10 and 40 cycles, as shown in Figure S5, because the dissolved Cu 2+ in the electrolyte could diffuse across the separator to Li anode. As an intermediate of the catalytic RM of Cu­(TFSI) 2 discussed above, the existence of Cu + in the electrolyte was affirmed using a qualitative color reaction proposed by Johar et al and also applied by Deng et al in Li–O 2 batteries.…”

“…Moreover, the solubility of CuS in the electrolyte was also confirmed with the EDS mapping images of Cu element on anode Li foil after discharge/charge for 10 and 40 cycles, as shown in Figure S5, because the dissolved Cu 2+ in the electrolyte could diffuse across the separator to Li anode. As an intermediate of the catalytic RM of Cu(TFSI) 2 discussed above, the existence of Cu + in the electrolyte was affirmed using a qualitative color reaction proposed by Johar et al 63 and also applied by Deng et al 64 Keeping in mind the cycle number dependence of the discharge capacity during the abnormal high-potential plateau, it is believed that the increase of capacity during the first 40 cycles is due to the increased amount of dissolved Cu 2+ with the increase in battery operation time, while its decrease after 40 cycles could be related to the shuttle effect of Cu(TFSI) 2 , which means that Cu(TFSI) 2 may diffuse across the electrolyte and the separator to the Li anode leading to low utilization.…”