This free online course teaches you how the chemical energy stored in batteries is converted into electrical current.

This free course covers the basics of batteries, which are devices consisting of multiple electrochemical cells that create electrical current from stored chemical energy. This course demonstrates that batteries are so much more and can be an alternative option for energy sources and may wean people off fossil fuels. We also go over battery sign conventions and how they work. The first part of the course focuses on the different parts of the battery: a positive electrode (or ‘cathode’), a negative electrode (or ‘anode’) and electrolytes that allow ions to move between the two to allow current to flow out of the battery. We also compare non-rechargeable ‘primary’ to rechargeable ‘secondary’ batteries and examine the electrochemical series called ‘reduction-oxidation’.

The course then delves into the standard procedure for testing and comparing batteries and the relevance of C-Rate to the test procedure. We explain a constant that is created by manufacturers and depends on the milliamp-hours specified in the battery. This constant is used to pinpoint how much a battery should be charged without damaging it. We study charge and discharge curves, which describe the behaviour of battery voltage with respect to time in hours of charge or discharge at normal rates. Then come polarization curves, which show the interdependence between the potential of the electrode and current intensity and its significance with respect to battery technology. The course then moves on to newer lithium-ion batteries, which use a graphite anode and a cobalt oxide cathode to allow high-capacity densities. Lithium metal batteries facilitate greater energy density and a much higher discharge rate and we break down each in detail. We then establish the advantages of lithium-ion batteries over their lithium metal counterparts.

Finally, we discuss the concepts of ‘plating’, ‘pickling’ and ‘sandwiching’. We identify various battery types in terms of shape, chemistry and meaning. Batteries can be made from many different materials and minerals: poly-acid, nickel-iron, nickel-cadmium, nickel-metal hydride and lithium-ion batteries, which can be charged without having to be fully discharged. Lithium-ion batteries have high capacity densities and are one of the most commercialized batteries worldwide. There is a wide variety of batteries, from miniature cells used in hearing aids and wristwatches to room-sized versions that provide backup power to telephone exchanges and data centre computers. We analyze batteries from a chemical perspective and list and discuss the advantages and disadvantages of each type. This course is aimed at anyone who wants to research batteries as alternative energy sources. It is particularly useful to those who want to study the improvement of electrochemical conversion processes for the treatment of the possible environmental consequences of waste. We can help anyone who wants to know more about this clean and renewable form of storage and energy creation that can preserve the environment while powering industry.