Cell and module test chambers under the microscope

October 2017 Energy storage units undergo load tests

Energy storage units undergo load tests

 

The BINDER cell and module test chambers for aging and performance tests offer the highest level of safety and maximum application convenience.

 

Stationary energy storage units and electric vehicles of all kind – from e-bikes to electric wheelbarrows – are in demand like never before. Manufacturers of components used in the production of high-voltage batteries are rejoicing in this ever increasing demand and are producing cells and modules for this purpose, which will later be integrated into battery systems. The cells are interconnected in a cell cluster, which forms a module. Several interconnected modules result in a battery pack. The high energy and power density of these energy storage devices also means that there are potential hazards when they are operated outside their specifications. The thermal spread of one cell to its neighboring cells is a particularly relevant safety-related aspect. If a cell were to cause a thermal runaway, i.e., catch fire or even explode, the neighboring cells must be sufficiently thermally insulated in order to prevent excessive overheating, which would lead to a consecutive reaction in the cell network. Therefore, the cells and modules are subjected to extreme endurance tests to determine their service life and performance.

 

The temperature resistance is tested and durability analyses are carried out in various temperature ranges in cell and module test chambers from BINDER, the world's largest simulation chamber specialist for scientific and industrial laboratories. It is vital to use special safety equipment when doing this. BINDER supplies test chambers with a standard safety package for aging tests, as well as a more extensive safety package for carrying out performance and aging tests.

 

De-energized cells and modules are exposed to varying temperatures to test their service life (standard safety package A), which simulates cyclical and calendric aging. The unit is equipped with a second fixed independent adjustable temperature safety device, which turns the test chamber off when it reaches the factory preset temperature of 120 °C in order to protect it against excessive heating. The controller, which is limited to a temperature of 120 °C, supports this safety measure.

 

Extensive performance tests are carried out in order to determine the performance of the cells and modules (safety package P). The cells and modules are therefore brought to the limits of their performance and load capacities by exposing them to constantly changing temperatures, with and without a current. This unit also has a second fixed independent adjustable temperature safety device with a preset temperature of 120 °C and a controller which is also limited to 120 °C. Access ports with rubber plugs are also specially installed on the walls of the units to ensure safe cable feed-through.

Since it is possible, in a worst-case scenario, for gas to form in the test chamber due to reactions of cell components, one or two clamps are installed on the locking side of the door-locking mechanism. For double doors, clamps are mounted between the doors. To divert the gas if necessary, an inert gas connection with pressure relief valves is installed in the test chambers additionally. These valves can be heated to prevent the formation of condensate and, therefore, possible icing.

 

The cell and module test safety packages A and P are available for BINDER units in the KB, MK and MKF series in sizes 115 to 720. These BINDER series units are converted by our BINDER INDIVIDUAL department according to special customer requirements, and equipped with the safety packages.