Closed-circuit Voltage Research Articles

Electrochemical investigations on magnesium/N-halogen organic cell systems

This paper reports the results of the experimental studies on various magnesium/magnesium perchlorate/N-halogen organic cell systems employing a constant current discharge method. Several battery parameters, viz. internal resistance, capacity, energy density and coulombic efficiency have been calculated. High open circuit potential (around 1000 mV), open circuit voltage (2.45-2.67 V) and closed circuit voltage (2.30-2.44 V) and non-toxicity are the important and attractive features of these organic cell systems. The trend of the capacities of various magnesium cell systems with respect to the chosen N-halogen organic cathodes is obtained as follows: DDH > TCIA > DCIA > TCM. The energy densities of DDH, TCIA, DCIA and TCM based cells are found to be 798, 660, 420 and 95 Wh (kg of N-halogen organic compound) −1, respectively. Cyclic voltammetric behaviour of a typical compound, viz. N, N'-dichlorodimethylhydantoin, has also been studied.

A Statistical Study of Sources of Variation in Primary Battery Testing

An analysis of variance (mixed model) experimental design was employed to quantify sources of variation in primary battery testing procedures for lithium/fluorinated carbon systems. Factors investigated were mix repeatability, mix uniformity, electrode fabrication method, and cell assembly and testing. Parameters measured were percent utilization and closed‐circuit voltage (CCV) at various depths of discharge (DOD). The standard deviations (for a random cell from a random blend on a random day) for percent utilization and CCV at 50% DOD were 4.2 percentage points (0.49 relative standard deviation) and 16 mV (0.006 relative standard deviation), respectively, indicating that the test method was adequate for evaluation of the performance of different samples. No significant difference due to electrode fabrication method in any of the measured parameters was observed. The CCV at 50% DOD was identified as the representative quantity of the performance of a sample. Improvements have been made in the areas of variability identified by this study, leading to more consistent test results.