Changes in electronic structure of Li2−xCuO2

Structural Analysis of NaCuO₂ Cathode at Various Charged/Discharged Stages and Its Reaction Mechanism

“…This behavior was very similar to that of lithium-ion extraction in Li/LiCuO 2 , Li/Li 1.5 CuO 2 and Li/Li 2 CuO 2 cells. [13][14][15][16] Figure 5 13 Their results suggest a possible reaction between CuO and sodium ions. However, in the NaCuO 2 system, the Na x CuO phase could not be detected after the discharge process because of the low discharge capacity (x = 0.2) or low crystallinity of Na x CuO.…”

“…The characteristics of Li x CuO 2 positive electrode material in a Li/Li x CuO 2 cell using Li metal for the negative electrode have been reported. [13][14][15][16] Li 2 CuO 2 can be synthesized, and LiCuO 2 can be obtained from it by electrochemically extracting one Li. 13,14 The Li/ Li 2 CuO 2 cell has a capacity of about 250 mAh/g, starting with charging from the open circuit voltage (OCV = 2.8 V) to 4.0 V. This capacity is consistent with the theoretical capacity of 245 mAh/g when 1 mol of Li ions is extracted per mol of Li 2 CuO 2 .…”

“…Therefore, it was revealed that the redox reaction between Cu 1+ -Cu 2+ is stable in the electrode reaction system using the NaCuO 2 . Regarding the reaction of the Li x CuO 2 positive electrode in the Li/ Li x CuO 2 cell, [13][14][15][16] both LiCuO 2 and Li 2 CuO 2 generated CuO during charging, after which a reversible reaction occurred between CuO and LiCuO. Electrochemistry, 86(6), 309-314 (2018) In summary, the NaCuO 2 system has different intermediate products and by-products from those of the Li x CuO 2 system, but Cu 4+ O 2 is unstable in both systems, and compounds of Cu 3+ , Cu 2+ , and Cu 1+ are observed.…”

“…As for Cu-based materials, NaCuO 2 has not yet been reported as a positive electrode material for Sodium ion batteries, and its properties have not been investigated, while Li x CuO 2 , as a positive electrode material for LIB, has been reported to have complicated reaction mechanism. [13][14][15][16] Here, we focused on NaCuO 2 as a positive electrode material for SIBs. [17][18][19][20] The crystal structure of NaCuO 2 is shown in Fig.…”

Investigating Li2NiO2–Li2CuO2 Solid Solutions as High-Capacity Cathode Materials for Li-Ion Batteries

“…14 18 Recently, Ruther et al performed a comprehensive study on the electrochemical reaction mechanism of Li 2 Cu 0.5 Ni 0.5 O 2 using a suite of characterization techniques, revealing a reversible Ni 2+ / Ni 3+ redox reaction coupled with O 2 evolution at a high charge voltage (>3.9 V) and Cu 2+ to Cu + reduction at a low discharge voltage (<1.8 V). 21 Oxygen oxidation was also proposed and gas evolution was detected by other groups, 25,31 but no quantification work has been performed to isolate the evolved gas species and correlate the oxygen redox with electrochemistry.…”