In the constant current charging and discharging. What causes the voltage at low current to increase but not reach the upper limit of the window?

from left to right are the constant current charge-discharge curves of materials a) CoFe2O4, b) CoFe2O4@AC 10%, and c) CoFe2O4@Cell 10% synthesized by the co-precipitation method. Please help me...

28 July 2025 8,009 4 View