Stationary Battery Systems

Our Mission
To Develop Innovative Solutions for Your Advanced Electrical Energy Storage Systems

We offer advanced and innovative solutions for electrical energy storage systems. Our focus is on full-custom cost-efficient electric energy storage and management system solutions for mobile and stationary applications. The activities range from development of embedded energy management software up to the design of complex high-power energy storage systems for smart grid applications in combination with renewable energies (e.g., in private household and industrial utilization) as well as electrically propelled vehicles (e.g., automobiles, bikes, motorcycles and other types of road vehicles, aircrafts, ships, and submarine vehicles).

R&D Topics

© Fraunhofer IISB

Battery Electronics

  • High Availability Redundant Battery Electronics Providing the Highest Reliability and Robustness for Safety-Critical Applications (e.g., ASIL-D, SIL4)
  • Distributed Battery Monitoring Electronics Building Smart Battery Cells, thus Providing Intelligence to Every Single Battery Cell and therefore Completely Eliminating the Signal Wiring in Future Battery Systems
  • Power Antifuse as Low-Cost Device for Bypassing Faulty Battery Cells

Battery Thermal Management

  • Thermal Management Reducing the Temperature Gradients in Battery Packs for Homogenous Ageing of all the Battery Cells, thus Reducing the Need for Balancing to a Minimum
  • Sensorless Battery Cell Temperature Estimation, thus Enabling Safe and Cost-Efficient Accurate Battery Pack Temperature Monitoring, Improving the Accuracy of Battery State Estimation Algorithms

Battery Modelling

  • Electro-chemical Modeling of Battery Cells for Robust and Accurate Battery State Estimation Algorithms; Generation of Compact Battery Cell Models for their Implementation on the BMS Microcontroller Platform
  • Advanced Model Parameter Optimization Algorithms for Global Offline Optimization and for Local In-system Online Optimization over the Complete System Lifetime
  • Model-Based Battery State Estimation Algorithms Using a Hardware-Accelerated Computing Platform for Highest Speed and Accuracy
  • Parametric Model-Order-Reduction Applied to Electro-thermal Battery System Models for Simulating Complete Use Cases (e.g., Automotive Driving Cycles) at System Level (e.g., NEDC, WLTP)

Battery Safety

  • Integration of Gas Sensors in Battery Systems for Early Fault Detection and Improved System Safety
  • Printed Temperature Sensor for Low-Cost Temperature Sensing to Improve the Safety in Battery Systems
     

Targeted Applications

Battery Systems for Mobile Applications

  • Automotive and Road Transport: Electrified Vehicles (e.g., 48V Boardnet Batteries, Plug-in Hybrid and Full Electric Vehicles, Utility Vehicles (including Forklift Truck), Trucks and Busses with Hybridized Powertrains), Electric Bicycles (e.g., e-Bikes and Pedelecs)
  • Railway and Rail Transport: Electrified Rail Public Transports (e.g., Traction Energy Storage Units with Batteries and/or Supercap / Ultracaps for Electric Locomotives)
  • Aviation and Aerospace: Gliders (e.g., Battery Supplied Electric Sustainer and Self-Launcher), Aircrafts (e.g., High-Power Batteries for APU), Satellites
  • Marine and Underwater: Multi-Megawatt-Hours (MWh) Battery Systems (e.g., Submarines, Cruise Ships)

Battery Systems for Stationary Applications

  • Industrial: Ultra-High-Performance Battery Systems (e.g., Complete Full-Custom Battery System Prototypes for Test Benches)
  • Renewables: Electric Energy Storage Systems for Renewable Energies (e.g., Photovoltaic and Wind Parks)

Offered Services

  • Design Reviews & Failure Analysis Based on our Broad Cross-Domain Experience
  • Market Screening and Market Studies Using our Extensive Network Worldwide
  • Characterization of Battery Cells by Using for Example Cycling, Electrochemical Impedance Spectroscopy (EIS), or Hybrid Power Pulse Characterization (HPPC)
  • Multi-Domain Modelling of Battery Cells and Systems (e.g., Electrical, Electro-thermal, Electro-chemical, Mechanical)
  • Calibration and Parameterization of Battery Models with Optimization Algorithms (e.g., Global and Local Optimization Algorithms)
  • Simulations and Simulation Methods for Designing and Dimensioning Battery Systems
  • Electric and Electronic Design of Battery Systems (e.g., Battery Monitoring System, Battery Management System, Battery Junction and Safety Box)
  • Mechanical Design of Battery Systems (e.g., Battery Module and Pack CAD-Design, Heating and Cooling with Liquid or Air)
  • Assembly and Integration of Battery Cells in Modules (e.g., Ultrasonic Welding, Clinching of up to 4-Layers)
  • Software Design for Battery System (e.g., Battery Management Software) ; Portable BMS Algorithms Based on 32bit OSEK/AUTOSAR Operating System ; Portable Monitoring-IC Drivers for 32bit OSEK/AUTOSAR Operating Systems
  • State Estimation Algorithms that are Platform Independent and Portable (e.g., SOC, SOE, SOH, SOL, SOF)
  • Tests (Electrical and Thermal) of Complete Battery Systems up to 1000V, 1000A, and 500kW
  • System Integration and Complete System Prototypes (e.g., up to Vehicle Integration)
     

Offered Product Development Competences

Battery System Design

  • Definition of the overall system requirements (e.g., energy and power capability, interfaces)
  • Selection of the best-suited cells based on our internal database
  • Modeling of the electrical, mechanical, and thermal parameters of the cells for the specified system

Battery Mechanical Design

  • Definition of the mechanical requirements
  • Definition of the battery cell assembly method (e.g., laser welding, ultrasonic welding, clinching, screwing)
  • Design of the battery modules with their power and signal connections
  • Design of the battery pack overall assembly

Battery Thermal Design

  • Definition of the thermal requirements including cooling and heating functions
  • Thermal design of the battery system by means of coupled electro-thermal simulations based on customized advanced FEM methods with powerful MOR (model-order-reduction) algorithms for system level analysis (combination with CFD also possible)
  • Definition of the thermal management components depending on the type of cooling and heating methods specified (i.e., liquid or air

Battery Electrical Design

  • Definition of the electrical requirements including safety aspects
  • Design of the battery cell monitoring hardware
  • Design of the battery management system (BMS) hardware based on the requirements to the analog and digital I/O
  • Design of the battery junction box (BJB) hardware including, amongst others, power and pre-charge contactors, pre-charge resistors, fuses, current sensors, galvanic isolation fault monitoring
  • Cell voltage equalization design

Battery Management Software Development

  • Development and adaption of the battery management system (BMS) software (application level) by means of a continuous workflow based on industry standard tools
  • Standardized AutoSAR 4.0-based software architecture that was customized for development flexibility and specific BMS needs
  • Development of advanced algorithms for battery state estimation: state-of-charge (SOC) estimation based on Kalman filters (e.g., EKF, AEKF, UKF), state-of-health (SOH) and state-of-life (SOL), state-of-function (SOF), sensorless temperature measurement, charging strategies
  • Modular design for fast adaption to specific customer demands and special features
  • Development and adaption of the testing software for the functional tests of the complete battery system

Battery System Integration

  • Component fabrication and assembly (e.g., package manufacturing, bus bars manufacturing, bus bars welding)
  • System assembly and integration
  • Final tests and characterization

Battery Testing

  • Electro-chemical impedance spectroscopy (EIS) up to 1 MHz and up to 30 A
  • Charging and discharging test on battery cell level between -1 V and 8 V and up to 440 A continuous current
  • Testing of real or standardized driving cycles on cell, module and system level up to ±1000 V, ±1000 A, 500 kW

Examples of Development

 

Battery Modules - Packs - Systems


We develop electrical, mechanical and thermal designs of battery modules, packs and systems for mobile and stationary applications. These applications englobe the transport (e.g., automotive, aeronautics) and energy (e.g., grid power quality improvement, grid stabilization, storage for sustainable energies like wind and solar) markets.

 

Battery Management Systems (BMS)

We develop the hardware and software for embedded battery management systems. These developments include the elaboration of portable software applications in the field of advanced battery state recognition algorithms (SOC: State-of-Charge ; SOH: State-of-Health ; SOF: State-of-Function), charging algorithms, as well as the safety aspects (e.g., ASIL considerations, isolation monitoring), including the standby requirements (e.g., low standby power consumption, black start), and much more.

 

Centralized Battery Monitoring Systems

We develop state-of-the-art centralized battery monitoring systems on the basis of commercially available battery monitoring integrated circuit from manufacturers like Linear Technology, Atmel, AMS. The centralized battery monitoring topology uses one battery monitoring printed circuit board (PCB) for monitoring one battery module, in general consisting of 4 to 18 battery cells in series.

 

Distributed Battery Monitoring Systems through Smart Battery Cells

We develop cutting-edge distributed battery monitoring systems in direct cooperation with key players in the field of battery technologies, system architectures, Tier 2, Tier 1 and OEM. Distributed battery monitoring brings the electronics inside the battery cell, thus reducing dramatically the system development costs and development time. The concepts and systems developed in this area are destined for the smart battery cells of tomorrow.

 

Innovative Devices for Enhanced Safety and Reliability in Battery Systems

We develop sensor and actuator devices for enhancing the safety and the reliability in Lithium-Ion battery systems. The increasing energy density in Lithium-Ion battery chemistries demands more safety requirements and adapted sensor and actuator devices (e.g., low-cost temperature sensors, high-power antifuse) for reaching these safety requirements.

Projects & Publications

 

Brochures

 

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