AVL Focus - Issue 2024

Electrochemical Modeling

of Battery Cells

The electrification of the automotive industry is in full swing. Be it

battery electric, fuel-cell-operated, or hybrid drive systems – they all

need a battery as an energy store or buffer. The battery is the key factor

of fundamental vehicle attributes such as range, charging time, mileage,

safety, and lifetime for all these types of vehicles.

ptimizing these attributes requires more than just good

cells and the right integration into a battery package, it

also requires an operating strategy that unleashes the

full potential of the cells without damaging them.

Classic electrothermal modeling using RC models can

map the voltage properties of cells in broad areas but does

not provide insight into the cell’s inner processes. This

means that it is not possible to predict behavior at limits,

such as during intensive charging/discharging or during

operation in extremely low or high temperatures. In contrast,

electrochemical modeling also allows mapping of the

chemical and physical processes in cells. Non-linear effects

such as intercalation reactions or diffusion processes are

maTTed correctly tLeir imTact on damage can Fe analy^ed,

thereby ensuring safe operation.

Nevertheless, the opinion persists that electrochemical

models are diƾcYlt to Tarameteri^e. -n %:0 '69-7)Ʀ 1 we

Lave imTlemented a gYided worOƽow tLat sYTTorts Ysers

with performing parameterization as quickly and as easily as

possible. In addition, missing input data can be substituted

with suitable data from a material database (empirical values).

A selection of parameterized cell models is also available as

a reference. These models are virtually integrated into the

relevant modules and packs in CRUISE M, for precise mapping

of their electric, thermal, and mechanical constraints. Once an

overall Multiphysics model is available, it completes further

tasks in addition to simulating real operating conditions

for performance evaluation. For example, examining

aging phenomena, calibrating the BMS with SoC and SoH

characteristics by means of virtual Hybrid Pulse Power

Characterization (HPPC) tests, or optimizing fast charging

features.

Sustainable mobility calls for sophisticated batteries.

And developing these batteries requires electrochemical

modeling.ɸ

2024