Cell/Module/Pack manufacturing
Packaging
Packaging process refers to a process in which a battery cell and a module are combined in series and parallel and put them in a frame, to protect them from external impact (vibration or heat) and to increase efficiency.
So an important factor in battery packaging is how much battery packs protect internal elements of the battery.
Therefore, safety of the battery pack can be improved by measuring how thermally the battery pack expands and how much thermal conductivity of battery pack is.
And one of the important issues in Electric Vehicles or Energy Storage Systems (ESS) is battery fire. It is possible to improve the safety of a battery pack by testing the characteristics of the battery pack when it is exposed to fire.
NETZSCH provides analyzing characteristic solutions ranging from thermal stability to fire safety of these battery packs.
Analyzing Solution
Measuring the thermal diffusivity and thermal conductivity along with the specific heat capacity form the basis for comprehensive understanding. But in Packaging process, LFA and DSC is not proper to investigate these thermophysical properties due to the sample size. Battery Pack sample is too big to be measured by LFA and DSC. But HFM can measure Battery Pack sample. HFM 446 Lambda Eco-Line, makes sure that the highest level of energy efficiency is at work when measuring thermal conductivity and even specific heat capacity.
Each time a material is exposed to temperature changes – it shows a variation in its dimension. Whether it is in the course of its regular thermal expansion or by passing a phase transition, the substance will either be shrunk or elongated. For example, polymer separators can shrink significantly at elevated temperatures which affects the battery performance and safety. To predict the deformation and stresses in the separator in battery cells, it is necessary to measure the expansion/shrinkage behavior. This is achieved by Thermomechanical Analysis (TMA) and Dilatometer (DIL), expressed by the coefficient of thermal expansion (CTE).
The risk of fire varies depending on the heat release rate. Therefore, the fire risk of the battery can be controlled by measuring the heat release rate of the battery. Battery fires can be prevented using Cone Calorimeter, TCC 918, which measures the gas flow and oxygen concentration to calculate the quantity of heat release per unit of time and surface area.
However, if you want to test the fire characteristics of a sample in battery pack units, you need larger equipment. Through Single Burning Item, SBI, the safety of the battery pack can be improved by placing a sample of the battery pack unit in a test chamber and exposing it to a fire environment to identify fire characteristics.