Charging Time is key for high product quality.
But how to achieve charging times of
less than
15 min
?
Challenge
The fast-charging capability is a decisive purchase requirement, not only for electric vehicles. Five boundaries are technically restricting the charging time as shown below. Violating the cell-specific limits leads to accelerated cell aging or even safety risks. The progression of the maximum permissible charging current over time, considering all five limits, depends on the electrochemical and thermal initial and boundary conditions in a strongly nonlinear manner. In addition, as the anode surface potential inside the cell is not experimentally accessible, the suitability of a charging current profile can only be tested indirectly by costly and time-consuming cycling tests.


The five limits of fast-charging
1
power
Limited by power grid.
2
current
Limited by charger current.
3
temperature
Limited by battery cell
(temperature-induced aging).
4
voltage
Limited by battery cell
(voltage-induced aging).
5
anode
Limited by battery cell
(lithium-plating aging).
Moreover, the fast charge capability of the battery is dependent on module design, cooling, cell type and therefore has to be solved on system level. This is why the development of optimal current profiles in the multidimensional, nonlinear parameter space consisting of time, state of charge, state of health and temperature is challenging.
Solution
You need a tool to predict all five limits under given operating conditions for individual cells and modules. And that is what the Batemo Cell Model is. Batemos unique battery modelling technology allows to derive optimal fast-charge profiles for the entire parameter space. This is the basis for an optimized testing design to experimentally validate the numerically calculated fast-charge profiles at carefully selected different operation conditions. This straightforward workflow simultaneously reduces charging time, development time and development cost.
If you have a physical, parametrized and validated model…

…you can calculate an optimal fast-charging strategy based on simulations.

Fast
Batemo Cell Models run within seconds on normal office computers. This enables large parameter variation to consider the nonlinear dependencies on temperature, SOC and aging state.

Physical
Only if you split up the physical processes in the cell correctly, you can calculate the anode surface potential and access all five limits of fast charging simultaneously.

Accurate
Quantitativly reliable simulation results need extensively validated models. The Batemo Cell Model is the most accurate battery cell model there is – guaranteed! We always demonstrate the validity through extensive measurements that prove highest accuracy.
Our methodology is to actively control the anode surface potential and thereby avoid lithium plating as shown in the example below. Thereby you reach the physically fastest possible charge profiles under all operating condition. The low computational times allows to automatically repeat this calculation under all initial and boundary conditions to derive ready to implement fast charge maps.


development method
-
Get the Batemo Cell Model to have a physical, parameterized and validated battery cell model.
-
Integrate the cell model into your module model.
-
Do batch simulations and derive optimal fast charging profiles and operational strategies.
avoid lithium plating!
-
Use the Batemo Cell Model to do a design of validation experiments.
-
Perform the validation experiments and directly implement it in your BMS!
Advantages
Use the Batemo Cell Model for simulation-based fast-charge development, making it faster and at lower cost while leading to lower charging times. This is how we generate value and contribute to your success.

Better
Reliably detect and prevent plating by having direct access to the anode surface potential. Simulate large parameter sweeps to prevent lithium plating at all operation conditions instead of experimentally spot check.

Faster
Cut down the charging time to the physical minimum by having access to all five limits at the same time. Optimize your total system or even consider cell design variations to push fast charging to a whole new level.

Lower cost
Take a straightforward workflow instead of cycle test in trial-and-error principle. Reduce test efforts to the minimum by utilizing digital development methods. Do your DOE simulation based, to identify the relevant test cases rapidly. Test smarter, not harder.