Chapter 11 - Connections to Kinetics

Abstract

This chapter deals with several issues related to kinetics. One of the issues dealt with is the storage of batteries in refrigeration. The conversion of chemical energy of a cell/battery into electrical energy is known as the discharge process. All batteries have characteristics that lead to a slow loss of charge over time, known as the battery self-discharge. Additionally, some battery components can deteriorate over time or volatilize. As any of the reactions are characterized by a reaction rate, the rate constant for the reaction can exhibit temperature dependence. If the reaction mechanism involves a single rate-determining step, then the rate constant for that elementary step will behave according to the Arrhenius law. This law gives a quantitative expression to relate the increase in a reaction rate with higher temperature. The higher the storage temperature, the worse is the capacity retention. Thus, for some batteries, self-discharge and deterioration reactions can be slowed considerably by storing the battery at low temperature when not in use. The shelf-life of primary batteries such as the zinc-carbon or alkaline-manganese systems can be significantly extended by storage at lower temperatures.