Kinetics of electrochemical intercalation of lithium ion into Li[Li0.2Co0.3Mn0.5]O2 electrode from Li2SO4 solution

The kinetics of electrochemical lithium ion intercalation into Li[Li0.2Co0.3Mn0.5]O2 electrode in 2 M Li2SO4 aqueous electrolyte has been studied using two electroanalytical methods, namely, potentiostatic intermittent titration technique (PITT) and galvanostatic intermittent titration technique (GITT). The results are compared with those from nonaqueous electrolytes. Layered, lithium-rich Li[Li0.2Co0.3Mn0.5]O2 cathode material was synthesized by reactions under autogenic pressure at elevated temperature (RAPET) method. The effects of ohmic potential drop and charge-transfer resistance have been considered while predicting the current transients obtained with aqueous electrolyte. For PITT and GITT, we have defined their characteristic time-invariant functions, It1/2 and dE/dt1/2, respectively to present the diffusion time constant τ. Application of different theoretical diffusion models for treating the results obtained by the above-mentioned techniques allowed us to calculate the diffusion coefficient of lithium ions (D) at different potentials (E). The intercalation process is explained by considering the possible attractive interactions of the intercalated species in terms of Frumkin intercalation isotherm. We have observed a strictcorrespondence between the peaks of the intercalation capacitance and the minima in the corresponding log D vs. E curve.

Optimization of the anode shape for the electroplating coating on long thin-walled detail taking into account the ohmic potential drop

The article discusses the problem of optimizing the anode shape to reduce the non-uniformity of the electroplating coating for a long thin- walled detail. An increase in the non-uniformity of the coating due to the ohmic potential drop in the electrodes body is characteristic of such details. The problem of optimizing the anode shape is formulated to minimize the non-uniformity of the electroplating coating. The mathematical model of the electroplating process has been developed, which takes into account the ohmic potential drop in the electrodes body. The problem of optimizing the anode shape is solved by the example of zinc electroplating process in an alkaline electrolyte, taking into account the ohmic potential drop in the electrodes body and without it.