WHAT IS A LITHIUM-ION BATTERY?

Lithium ion batteries can be defined as all batteries based on lithium compounds. The reactive materials of the negative and positive electrodes as well as the electrolyte contain lithium ions.

There are a large number of different lithium-ion batteries, which differ not only in size and design, but also in the chemical composition of their components and the voltage ranges. Lithium cobalt dioxide accumulators dominated the market for around two decades, whereas today it is mainly NMC-based accumulators that are widely used. In addition to NMC, lithium-iron-phosphate is a very common battery chemistry that is used in stationary storage systems in particular.

Lithium-ion batteries are generally characterized by a higher specific energy (energy per net mass) compared to other battery types. As they are sensitive to deep discharge and overcharging, they require a suitable battery management system (BMS). Characteristics such as cell voltage, temperature sensitivity, final charging and discharging voltage and the maximum permitted charging or discharging current vary depending on the design and are largely dependent on the electrode material and electrolyte used. Therefore, the exact specification of the type, such as lithium iron phosphate accumulator, is more informative than the general designation lithium-ion accumulator. In addition to the variants based on different electrode materials, there are also variants based on different electrolytes: A cell can contain a liquid electrolyte or be designed as a lithium-polymer accumulator.

Lithium-ion batteries were used primarily in portable devices with high energy requirements, as conventional nickel-cadmium or nickel-metal hydride batteries were too heavy or too large. Among these were cell phones, tablets, digital cameras, camcorders, notebooks and flashlights. Nowadays, they are used and applied in almost all fields, for example in electromobility, they are used to store energy for pedelecs, electric cars, modern electric wheelchairs and hybrid vehicles. In 2020, the Fraunhofer Institute for Systems and Innovation Research ISI predicted that the demand for lithium-ion cells for electromobility will increase 20 to 40-fold by 2030.

Since 2003, lithium-ion batteries have also been used in power tools such as cordless screwdrivers and garden tools. Lithium cobalt dioxide (LiCoO2) batteries are used in the Boeing 787, which were subsequently given a steel casing after several fires. Other aircraft have been equipped with lithium iron phosphate batteries since 2012. Lithium-ion battery systems are also used in battery storage systems.