Trendsetting reusable battery technology made in Germany

(Press release: Krefeld, February 18, 2020) – The energy turnaround and the electric mobility promoted by the German government depend very much on innovative battery technology. The EU regulation, which comes into force from 2021 and regulates the EU-wide average CO2 emission target for the new car fleet of individual car manufacturers, specifies a value of 95g/km. If this target is not reached, massive fines will be imposed on the manufacturers. Therefore, the European car manufacturers are making great efforts to get CO2-neutral electric fleets on the road.

Almost all European manufacturers use large so-called prismatic cells for this purpose. This leads to a shortage of this type of battery on the world markets. At the same time prismatic cells are also used as industrial battery storage systems or home storage. The American manufacturer Tesla uses round cells instead of prismatic battery cells. Tesla as well as E-Stream Energie see unbeatable advantages in round cells compared to prismatic cells in areas such as energy density, thermal management, safety, performance, flexibility, sustainability and costs.

The energy density of round cells can reach up to around 94 percent – in contrast, prismatic cells have a maximum energy density of 60 percent. E-Stream Energie assumes that round cells will be superior to all other cell types for at least another decade. E-Stream Energie has also developed an innovative packaging system for round cells. This system achieves the highest energy density in comparison with competitors. It is a lightweight construction in which the round cells can be arranged as compactly as possible. Thus the E-Stream battery modules have an enormously high energy density. This means a greater range for electric vehicles.

The higher power density of the round cells in the smallest installation space enables even small electric vehicles to drive dynamically. The E-Stream battery modules feature high-voltage capability of up to 1000 volts – as well as a very high rapid charging speed of 20-80% SoC in under 15 minutes. Low-impedance connection technology ensures high electrical efficiency and, as a result, lower heat losses and higher power density at both cell and module level. In contrast to prismatic cells, the E-Stream battery module has almost unlimited flexibility for electrical parameters such as capacity, voltage, energy or performance.

The round cells used by E-Stream offer a high degree of safety – there is a significantly reduced risk compared to prism cells of a Thermal Runaway. Due to the use of a large number of small battery cells, the Thermal Runaway would have a delayed fire propagation. Compared to prismatic round cells, round cells have a significantly lower amount of energy per individual cell – by a factor of 27. The hermetically sealed housing of round cells also offers special protection. The system availability of the battery module in the event of a cell malfunction should be emphasized. The defective cell is separated from the compound, the drive train remains functional.

The thermal properties of round cells are excellent: they enable the use of efficient, cost-effective and space-saving thermal management solutions. Cylindrical cells can be cooled better due to their low thermal resistance. Due to the advantageous thermal behaviour of cylindrical cells in combination with the innovative E-Stream cell connection technology, hot spots are avoided, so that heat flow and heat distribution are optimal. Cooling of round cells is thus significantly more cost-effective than with prismatic cells – at the same time, the charging process can be made significantly faster.

The E-Stream battery modules follow the principle of Lego bricks. They offer almost unlimited flexibility in terms of installation space, capacity and voltage. This is a huge advantage, especially in electric mobility. Space problems in combination with insufficient energy efficiency represent a negative performance factor that should not be underestimated.

The service life of a battery depends mainly on the cell chemistry, the electrical use and the quality of the cell connection technology. The E-Stream technology offers innovative gentle cell connection technology without thermal processes and avoids pre-damage effects in the production of battery modules.

Sustainability is an important point in the production and completion of battery modules: When the end of the cell life structure is reached, the E-Stream battery can be overhauled and individual cells from the composite can be replaced. This means that old cells from E-Stream automotive packs can be easily dismantled and used in other energy storage applications, thus giving them a second life. E-Stream technology enables Second Life for both individual cells and interconnection technology. In addition to the publicly discussed sustainability aspect, it also offers a decisive cost advantage. Simple, fast and industrializable production of E-Stream battery modules offers cost and time advantages.

In recent years, German industry has been accused of undermining the development of battery storage capacity and thus also the possibilities of electromobility. In E-Stream there is now a German medium-sized company, which offers solutions to all important questions concerning the all-important performance of storage modules. E-Stream now only has to slip onto the radar of major European car manufacturers.