Abstract: Improving performances of current Li-ion batteries and developing new rechargeable electrochemical energy storage devices are highly desirable. The latter depends on successful developments of new materials, battery units and battery system optimization. This calls for radical changes in the methodology from the currently commonly used trial-and-error to rational designs based upon fundamental understanding of underlying physics and chemistry. This series papers will discuss various aspects including thermodynamic, kinetic, interfacial, materials, battery units and systems, and characterization techniques. This will hopefully shed some light on the research and development of new chemical energy storage technologies particularly batteries. This is the first paper in the series and will discuss the energy densities of batteries, showing theoretical calculations of energy storage densities of electrochemical energy storage systems from the Nernst equation, the limitation of chemical energy storage systems, and estimation of voltages of the electrode materials.

Key words: chemical energy storage battery, theoretical energy density, theoretical electric potential, thermodynamics calculation