BEST – Battery and Electrochemistry Simulation Tool

The Battery and Electrochemistry Simulation Tool (BEST) is our software environment for the physics-based three-dimensional simulation of lithium-ion batteries.

»Physics-based« means that the cell behavior is not described by an adapted, phenomenological, but by a physical partial differential equation model which describes the charge, ion and energy transport in the cell. This is based on only one set of material parameters which can be determined experimentally.

BESTmicro and BESTmeso

Apart from the material parameters, their geometrical parameters are also relevant for the behavior of a battery cell. This is a multiscale problem because both the microstructure of the electrodes (eg particle sizes and arrangement) as well as the macroscopic dimensions (eg layer thickness or extent) are influencing.

For both levels, BEST offers the best solution with its BESTmicro and BESTmeso modules. In both cases the battery behavior is calculated fully three-dimensionally in order to be able to reproduce the geometrical factors as accurately as possible.

BEST not only calculates the time curve of the cell voltage for a given (de-) charging current. It is also possible to consider more complex time-dependent loads and CC / CV phases and to examine the behavior of the virtual cell. The calculated time and space varying ion and potential distribution allows a detailed study of the observed effects. By combining with thermal or mechanical effects or by calculating the Li-Plating risk, BEST also provides a solid basis for aging calculations.

Graphical user interface of BEST.
© Fraunhofer ITWM
Graphical user interface of BEST.

BEST Features in the Overview

  • Physical battery model developed at Fraunhofer ITWM
  • User-friendly graphical user interface
    • Simulation Setup
    • Control over any number of simultaneous simulations
  • Input options
    • Simple implementation of functions by the user for parameters, boundary conditions, etc.
    • CC and CV-Mode
    • Geometry Creation
    • Import of GeoDict structures
    • Import of 3d data from image stacks of measurements
  • Output options
    • 3d data in vtk or GeoDict format or as a simple ASCII file
    • SOC and time-dependent course of current and cell voltage
  • Multithreading
  • Available for Windows and Linux
  • Different licensing options
  • User-specific software or model adjustment possible at any time


  • Micro-Scale Modeling of Li-Ion Batteries: Parameterization and Validation, J. Electrochem. Soc. 159 (2012) A697-A704.
  • A. Latz and J. Zausch: Thermodynamic consistent transport theory of Li-ion batteries, Journal of Power Sources 196 (2011) 3296–3302.


Example Projects


Battery Simulation BEST Supports Virtual Development of Novel Battery Cells

ERDF Project ABBA-VEEB (Extension of the battery simulation BEST to a design platform for the virtual development and testing of battery cells)


New Methods in Development and Production of Battery Cells

The DEFACTO project aims to revolutionize cell production for electric vehicles in Europe.


Battery Cells with Integrated Sensors

Concept development and testing of cells that are individually equipped with voltage and temperature sensors with the support of BEST.


Volume Change and Phase Separation in Electrode Materials

In the AiF project ALIB the existing electrochemical simulation models of BEST were expanded.


Predict the Life of Lithium-Ion Batteries

The MULTIBAT project focuses on the prediction of battery life.


Simulation-Based Design of Fuel Cells

The aim of the research group OPTIGAA is to enable the computer-assisted design of fuel cells.


XERIC: Innovative Climate Control System for Electric Vehicles

The XERIC project is developing a new climate control system that is more energy-efficient in battery powered electric vehicles.