Skill and Scale up: Voltage applied

The Age of Electricity

Voltage is measured in volts. Volts as in Volta. It all started around 1800 with the voltaic column of Italian physicist Alessandro Volta. The original type of battery can be traced back to him. Frog's legs played an important role. Today, he is so prominent in the history of electricity that an entire device is named after him. His first permanent source of electricity made further research into electricity possible. It is time to take a brief look at the history of the battery before we look at different concepts for energy storage.


© Fraunhofer FFB
Until 1791, electricity was only visible to humans during thunderstorms. Today, a world without electricity is unimaginable.

During the Age of Enlightenment, many people experimented with electricity, with varying degrees of success. Often, the experiments were only convincing for entertainment purposes at fairs. In 1780, the Italian physician Luigi Galvani attracted much more attention: Using two connected pieces of iron and copper, he made the muscles in the legs of a frog twitch when they came into contact with the animal. Spectacular - that's how the scientific world saw it and concluded that it was "animal electricity". But from Volta's point of view, he was completely wrong. Rather, Galvani was generating electricity electrochemically using two different metals. 

The first battery is invented

When Alessandro Volta learned of the frog leg experiments in 1791, he conducted his own experiments and discovered that the salt water in the animal's body created a current between the two metals. Thus, electricity is generated by the contact of certain metals. Based on these findings, he constructed the "Volta column": He placed pieces of leather soaked in salt water between copper and zinc plates, which were stacked closely together to form a column. Chemical reactions turn the copper into the negative pole and the zinc into the positive pole. When the two ends are connected, electricity flows. While the individual cells have relatively small voltages, when stacked in a column, they add up to a high total voltage. With the "Volta column," Alessandro Volta built the world's first battery and opened the door to the age of electricity. The discovery of a permanent source of electricity made the study of electricity possible.

© Adobe Stock/ WINDCOLORS
Due to its specific properties, it is likely that lithium will continue to have an indispensable and non-replaceable key component for rechargeable batteries in the coming decades.

The gateway to the age of electricity

Until then, electricity was only visible to humans during thunderstorms - in the form of lightning. Since then, the field of research has undergone a rapid evolution, marked by many groundbreaking discoveries. John B. Goodenough, M. Stanley Whittingham, and Akira Yoshino have been particularly instrumental. They are known as the "fathers of the lithium-ion battery" and their research in the 1970s and 1980s sparked a technological revolution. Since then, the basic characteristics of the lithium-ion battery have changed very little. There have been incremental improvements in materials and cell design. However, it is also difficult to optimize the LIB, as electrochemical stability and high safety concerns set natural limits.

Variety of energy storage systems

Modern energy storage systems are essential for relieving pressure on the electricity grid and for electrifying industry and transportation. They are based on four fundamentally different approaches:

  • Electrochemical energy storage, such as a lithium-ion battery or a lead-acid battery.
  • Chemical energy storage, such as converting electricity to hydrogen, storing it, and then converting it back to electricity.
  • Mechanical energy storage, such as pumped hydro. Here, water is pumped from a lower reservoir to a higher reservoir and released only when needed to generate electricity via a turbine.
  • Thermal energy storage, such as metal-based high-temperature energy storage, allows process heat to be stored at high temperatures for later use.
© Fraunhofer FFB.
Energy storage plays an important role in the generation, transmission, distribution, and consumption of energy.

One thing is clear: a climate-neutral future and a sustainable energy supply require a variety of energy storage systems. The lithium-ion battery has played a leading role in electrochemical energy storage technologies to date, but is reaching its limits as storage time increases or the need for rapid energy supply arises. Today, supercapacitors are used for this purpose, for example in electric buses. The principle is simple: When the bus brakes, the electric motor converts kinetic energy into electrical energy, which is used to charge the supercapacitors and make them available for restarting after the stop. Starting a heavy vehicle such as a bus is much more energy-intensive than starting a car, and is difficult for lithium-ion batteries to handle. Because supercapacitors store energy electrically rather than electrochemically, the charging and discharging processes are much faster.