Aging and performance tests in cell and module test chambers

November 2016 Cell and module test chambers

Energy storage device 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 devices and electric vehicles of every type – from electric bikes to electric wheelbarrows – are in demand like never before. The manufacturers of components for the production of high-voltage batteries have been enjoying an ever-increasing level of demand and thus produce cells and modules which can later be integrated into the battery systems. The cells are interconnected in a cell network, resulting in a module; several modules connected together form a battery pack. The high energy and power density of these energy storage devices also means new potential hazards when 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. Cells and modules therefore undergo extreme endurance testing to determine their service life and performance.  The temperature resistance is tested and the service life is analyzed in various temperature ranges in cell and module test chambers from BINDER. Special safety equipment is vital for this. BINDER offers test chambers with a standard safety package for aging tests alone and a comprehensive safety package to carry 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 have also been 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, two clamps can be installed on the locking side of the door-locking mechanism as an option. For double doors, clamps are mounted between the doors. To divert the gas if necessary, it is possible to integrate an inert gas connection with pressure relief valves into the test chambers as an option. These valves can be heated to prevent the formation of condensate and, therefore, possible icing.