TECHNOLOGY

GVI® housings for longer battery life

The vicious circle with batteries

Batteries have a so-called “feel-good” temperature. Only in this temperature range do they deliver their full power; however, the power curve drops by up to 50 percent and battery service drops rapidly when they operate above or below this temperature. This problem is familiar from electric vehicles: The battery of an e-car left in a cool place for a long time in winter needs to be actively heated during this time in order to provide its power when needed. This leads to a drop in battery performance – and to a decrease in the range of the vehicle.

Heat is generated in warmer environments and when charging the energy stores. The more power that is input, the higher the heat generation and the lower the energy density. The lifecycle decreases in this case, as well, and the batteries can even burst in the worst case.

Manufacturers are trying to counteract this problem with active cooling. However, this also requires additional energy from the battery. GVI® technology breaks this vicious circle once and for all.

Technology

Multifunctional battery housings from GVI®

Battery housings based on GVI® can be produced to keep out both cold and heat. They therefore insulate the battery in e-vehicles, allowing it to develop its full capacity in its “feel-good” range. In contrast to active battery heaters or coolers, GVI® technology also functions passively and thus almost energy-free – only a minimum amount of energy is required for cooling.

Moreover, due to its technical properties, GVI® battery housings can ensure greater stability of a vehicle geometry and thus save material and weight. They also provides greater safety with regard to the dangers to people and the environment that a lithium-ion battery can pose today.

Multi-stage thermal management with adaptive regulation

  • The battery temperature is regulated in several stages and optimally adjusted: thermal insulation, heat storage, active cooling.
  • The various stages of thermal management are activated via adaptive real-time controls, taking into account driving and battery conditions.
  • Cooling elements and heat accumulators are integrated into the housing structure and are thus safely separated from the battery cells; further damage is avoided in the event of a crash.
  • The option of storing heat allows it to be used sensibly (battery heating, vehicle air conditioning), thus improving system efficiency.

An optimised thermal management system sustainably improves the capacity and service life of the battery.

Construction types

Use in lightweight design concepts

  • Can be planned and produced exactly for the available installation space
  • Can be designed as part of the load-bearing vehicle structure
  • No additional supporting elements (thermal bridges)

Characteristics

Construction and usage

  • Use in lightweight design concepts as part of the load-bearing vehicle structure
  • High-strength and rigid (comparable to sandwich structures)
  • Double-walled construction made of thin stainless steel sheets allows complete encapsulation of the battery
  • Vibration-proof fixing in multifunctional housing
  • No additional supporting elements

Cladding materials

We use metallic cladding materials for GVI® systems as standard. Due to their relatively low specific thermal conductivity, high strength and good weldability, austenitic stainless steels offer special advantages. Other materials such as the light metals aluminium or magnesium offer advantages especially for extreme lightweight design applications.

Organic (lightweight) materials are also often used for lower temperature loads: Large-surface containers can be manufactured from glass-fibre reinforced plastics (GRP). Our experience has shown that such housings are sufficiently vacuum-tight if the matrix resin is properly selected.

Filler materials

These are usually mineral materials with minimal solid-state thermal conductivity, very low emissions, sufficient support capacity and a fine porous structure. The pores must be open to ensure good evacuation.

Depending on the type of application, prefabricated moulded parts such as plates or pipe segments and free-flowing materials can be inserted into the double-walled insulating sheath.