scholarly journals Dimensioning and Optimization of Hybrid Li-Ion Battery Systems for EVs

2018 ◽  
Vol 9 (2) ◽  
pp. 19 ◽  
Author(s):  
Jan Becker ◽  
Thomas Nemeth ◽  
Raphael Wegmann ◽  
Dirk Sauer
Keyword(s):  
Fixed Ratio ◽  
Lithium Ion ◽  
Maximum Power ◽  
Battery Pack ◽  
Optimization Approach ◽  
System Specification ◽  
Control Logic ◽  
Battery Cell ◽  
Battery System ◽  
Battery Systems

Commercial electric vehicles nowadays are powered by a battery system containing one kind of lithium-ion battery cell. Due to the fixed ratio of the cells’ maximum power to nominal energy, the possibilities for designing power and energy of the battery pack independently are limited. The battery system’s energy and maximum power can only be scaled by adapting the number of cells and modules, and the parameters furthermore depend on the characteristics of the cells used. Additional power electronics in the form of one or more dc/dc converters can be used to form a hybrid battery system comprised of more than one pack and different cell technologies. This allows for individually designing each battery pack and thus optimizing the overall battery system specification. This work presents a battery dimensioning and optimization approach for single pack and hybrid battery systems. It is based on an evolutionary optimization algorithm and a detailed, modular Matlab-Simulink vehicle model. Studies on the advantages of hybrid batteries for different vehicle classes were carried out. Results indicate that optimized hybrid battery systems can lead to weight and volume savings and further advantages in total cost of ownership, for example, by enhanced battery life time or reduced investment costs. On the other hand, they require more complex control logic, which is also discussed in this paper.

Scenario-Based Development of Disassembly Systems for Automotive Lithium Ion Battery Systems

2014 ◽  
Vol 907 ◽  
pp. 391-401 ◽  
Author(s):  
Christoph Herrmann ◽  
Annika Raatz ◽  
Stefan Andrew ◽  
Jan Schmitt
Keyword(s):  
End Of Life ◽  
System Development ◽  
Lithium Ion ◽  
Integrated Sensor ◽  
Battery Cell ◽  
Battery System ◽  
Working Space ◽  
Battery Systems ◽  
Core Elements ◽  
Automated Disassembly

The rising number of lithium ion batteries from electric vehicles makes an economically advantageous and technically mature disassembly system for the end-of-life batteries inevitable. The disassembly system needs to cope with the size, the design and the remaining state of charge of the respective battery system. The complex design resulting from the number and type of connection elements challenges an automated disassembly. The realisation of an automated disassembly presupposes the consideration of elements from Design for Disassembly throughout the battery system development. In this paper a scenario-based development of disassembly systems is presented with varying possible design aspects as well as different amounts of end of life battery systems. These scenarios point out the resulting implications on battery disassembly systems in short, medium and long term. Using a morphological box the best option for each disassembly scenario is identified and framed in a disassembly system design. The disassembly systems are explained and the core elements are introduced. Newly developed and innovative disassembly tools, such as a robot that allows a hybrid human-robot-working-space and an advanced battery cell gripper are introduced. The gripper system for the battery cells enables with an integrated sensor an instant monitoring of the battery cell condition. The proposed disassembly element is verified in an experimental test series with automotive pouch cell batteries.

scholarly journals Effect of dynamic loads and vibrations on lithium-ion batteries

2021 ◽  
pp. 146134842110081
Author(s):  
Xia Hua ◽  
Alan Thomas
Keyword(s):  
Lithium Ion Batteries ◽  
Lithium Ion Battery ◽  
Experimental Studies ◽  
Lithium Ion ◽  
Battery Pack ◽  
Dynamic Loads ◽  
Electrical Performance ◽  
Mechanical Degradation ◽  
Energy Storage Devices ◽  
Battery Cell

Lithium-ion batteries are being increasingly used as the main energy storage devices in modern mobile applications, including modern spacecrafts, satellites, and electric vehicles, in which consistent and severe vibrations exist. As the lithium-ion battery market share grows, so must our understanding of the effect of mechanical vibrations and shocks on the electrical performance and mechanical properties of such batteries. Only a few recent studies investigated the effect of vibrations on the degradation and fatigue of battery cell materials as well as the effect of vibrations on the battery pack structure. This review focused on the recent progress in determining the effect of dynamic loads and vibrations on lithium-ion batteries to advance the understanding of lithium-ion battery systems. Theoretical, computational, and experimental studies conducted in both academia and industry in the past few years are reviewed herein. Although the effect of dynamic loads and random vibrations on the mechanical behavior of battery pack structures has been investigated and the correlation between vibration and the battery cell electrical performance has been determined to support the development of more robust electrical systems, it is still necessary to clarify the mechanical degradation mechanisms that affect the electrical performance and safety of battery cells.

Self-Balancing by Design in Hybrid Electrochemical Battery Packs

2018 ◽  
Author(s):  
Nur Adilah Aljunid ◽  
Michelle A. K. Denlinger ◽  
Hosam K. Fathy
Keyword(s):  
Feedback Loop ◽  
Lithium Ion ◽  
Battery Pack ◽  
Hybrid Cells ◽  
Battery Cell ◽  
Battery Packs ◽  
Li Ion ◽  
Electrochemical Battery ◽  
Novel Concept ◽  
Physics Based Simulation

This paper explores the novel concept that a hybrid battery pack containing both lithium-ion (Li-ion) and vanadium redox flow (VRF) cells can self-balance automatically, by design. The proposed hybrid pack connects the Li-ion and VRF cells in parallel to form “hybrid cells”, then connects these hybrid cells into series strings. The basic idea is to exploit the recirculation and mixing of the VRF electrolytes to establish an internal feedback loop. This feedback loop attenuates state of charge (SOC) imbalances in both the VRF battery and the lithium-ion cells connected to it. This self-balancing occurs automatically, by design. This stands in sharp contrast to today’s battery pack balancing approaches, all of which require either (passive/active) power electronics or an external photovoltaic source to balance battery cell SOCs. The paper demonstrates this self-balancing property using a physics-based simulation of the proposed hybrid pack. To the best of the authors’ knowledge, this work represents the first report in the literature of self-balancing “by design” in electrochemical battery packs.

scholarly journals Run to Failure: Aging of Commercial Battery Cells beyond Their End of Life

Energies ◽  
2020 ◽  
Vol 13 (8) ◽  
pp. 1858
Author(s):  
Andreas Ziegler ◽  
David Oeser ◽  
Thiemo Hein ◽  
Daniel Montesinos-Miracle ◽  
Ansgar Ackva
Keyword(s):  
Computed Tomography ◽  
Single Cells ◽  
Lithium Ion ◽  
Constant Load ◽  
Internal Resistance ◽  
Battery Pack ◽  
X Rays ◽  
Battery Cell ◽  
Jelly Roll ◽  
Battery Cells

The aim of this work is to age commercial battery cells far beyond their expected lifetime. There is a gap in the literature regarding run to failure tests of lithium-ion batteries that this work intends to address. Therefore, twenty new Samsung ICR18650-26F cells were aged as a battery pack in a run to failure test. Aging took place with a constant load current and a constant charge current to accelerate capacity decrease. Important aging parameters such as capacity and internal resistance were measured at each cycle to monitor their development. The end of the test was initiated by the explosion of a single battery cell, after which the battery pack was disassembled and all parameters of the still intact single cells were measured. The distribution of all measured capacities and internal resistances is displayed graphically. This clearly shows the influence of the exploded cell on the cells in its immediate vicinity. Selected cells from this area of the battery were subjected to computed tomography (CT) to detect internal defects. The X-rays taken with computed tomography showed clear damage within the jelly roll, as well as the triggered safety mechanisms.

Coupled-Physics Modeling of a Lithium-Ion Battery Cylindrical Cell Microstructure

2012 ◽  
Author(s):  
Peter N. Doval ◽  
Ilya V. Avdeev
Keyword(s):  
Cross Section ◽  
Automotive Industry ◽  
Hybrid Electric Vehicle ◽  
Emerging Market ◽  
Lithium Ion ◽  
Functional Materials ◽  
Battery Pack ◽  
Cylindrical Shape ◽  
Fe Model ◽  
Battery Cell

Safety of consumer vehicles is an extremely important consideration for the automotive industry. An emerging market in the automotive industry today is the electric and hybrid-electric vehicle market. As environmental concerns grow, such vehicles will become a necessity for manufacturers to remain within increasingly stringent emissions regulations. A recent problem with the high-voltage lithium-ion batteries used in many of these vehicles is that of thermal runaway following a severe collision. This paper represents our early attempt to look at one aspect of this extensive project — a coupled-physics model of battery cell microstructure. In this case, couple-physics refers only to thermal-structural coupling and the microstructure being studied here is the laminate-level structure. A 2-D finite element model of a lithium-ion cell was therefore developed. This 2-D model of the cell, also called a jellyroll, is a cross-section cut of one cell within a battery pack. Each battery cell is an assembly of alternating thin sheets of functional materials (anode, separator and cathode), which are rolled into a cylindrical shape. The cross-section then takes the form of a layered spiral. The typical cell is made of an aluminum cathode with coating, copper anode with coating, and a non-linear, viscoelastic polymer separator. Once the 2-D jellyroll FE model was created, some initial structural element simulations were run to validate the geometry setup and model integrity. Next, thermal-structural coupled-field simulations were run to investigate stress propagation resulting from thermal loads as well as the same loading cases performed with the structural-only model. Different loading conditions, including uniaxial stress-strain state, hydrostatic pressure test, and thermo-mechanical loading were simulated. The results from the simulations performed in the project set the groundwork of future models involving electrical properties and models of 3-D cells and the full battery pack.

Experimental Evaluation of Cell Balancing Algorithms with Arduino Based Monitoring System

2016 ◽  
Vol 20 (6) ◽  
pp. 968-973 ◽  
Author(s):  
Muhammad Talha ◽  
◽  
Furqan Asghar ◽  
Sung Ho Kim ◽  
Keyword(s):  
Monitoring System ◽  
High Efficiency ◽  
Battery Pack ◽  
Battery Life ◽  
Battery System ◽  
Battery Systems ◽  
Response Output ◽  
Multiple Cells ◽  
Cell Balancing ◽  
Partial Current

The trend toward more electric vehicles has demanded the need for high efficiency, high voltage and long life battery systems [1,_2]. Also renewable energy systems carry huge battery backups to overcome the renewable source shortage. Battery systems are affected by many factors, cells unbalancing is one of most important among these factors. Without the balancing system, individual cell voltages will differ over time that will decrease the battery pack capacity quickly. This condition is especially severe when the battery has a long string of cells and frequent regenerative charging is done via battery pack. Cell balancing is a method of designing safer battery solutions that extends battery runtime as well as battery life. Balancing mechanism can help in equalizing the state of charge across the multiple cells, therefore increasing the performance of battery system. Different cell balancing methodologies have been proposed for battery pack in recent years. These methods have some merits and demerits in comparison to each other; e.g. balancing time, complexity and active or passive balancing etc. In this paper, current bypass active cell balancing and Arduino based monitoring system designing and implementation is carried out. In charging process, this balancing technique provides partial current bypass using charging slope for weak cells. Also the passive shunt resistor technique is implemented to compare and verify the proposed system efficient response. Output result shows that this proposed balancing technique can perform cell balancing in much effective and efficient way as compared to previous balancing techniques. Using this cell balancing technique, we can improve overall battery health and lifetime.

Fault Detection and Isolation for Lithium-Ion Battery System Using Structural Analysis and Sequential Residual Generation

2014 ◽  
Author(s):  
Zhentong Liu ◽  
Qadeer Ahmed ◽  
Giorgio Rizzoni ◽  
Hongwen He
Keyword(s):  
Structural Analysis ◽  
Fault Detection ◽  
Cooling System ◽  
Hazard Analysis ◽  
Lithium Ion ◽  
Test Construction ◽  
Fault Isolation ◽  
Fault Detection And Isolation ◽  
Battery Cell ◽  
Battery Systems

This paper presents a systematic methodology based on structural analysis and sequential residual generators to design a Fault Detection and Isolation (FDI) scheme for nonlinear battery systems. The faults to be diagnosed are highlighted using a detailed hazard analysis conducted for battery systems. The developed methodology includes four steps: candidate residual generators generation, residual generators selection, diagnostic test construction and fault isolation. State transformation is employed to make the residuals realizable. The simulation results show that the proposed FDI scheme successfully detects and isolates the faults injected in the battery cell with cooling system at different times. In addition, there are no false or missed detections of the faults.

Energy Equalization Circuit with Multiple Primary Windings for Li-Ion Battery System

2013 ◽  
Vol 380-384 ◽  
pp. 3374-3377
Author(s):  
San Xing Chen ◽  
Ming Yu Gao ◽  
Guo Jin Ma ◽  
Zhi Wei He
Keyword(s):  
Lithium Ion Battery ◽  
Lithium Ion ◽  
Battery Pack ◽  
Li Ion Battery ◽  
Battery System ◽  
Multiple Primary ◽  
In Series ◽  
A Cell ◽  
Li Ion ◽  
Number Of Cells

In this paper, a cell equalization circuit based on the Flyback topology is proposed for the Lithium-ion battery pack. Multiple transformers are employed in this circuit, equal to the number of cells in the pack. All the primary windings are coupled in series to provide the equalizing energy form the whole battery pack to the specific under charged cells. The structure and principle of the circuit is discussed, finally a prototype of four cells is presented to show the outstanding equalization efficiency of the proposed circuit.

scholarly journals Research on Key Technologies for Improving the Electro catalytic Performance and Physical Properties of Lithium Batteries in Electric Vehicles

2021 ◽  
Vol 2083 (2) ◽  
pp. 022071
Author(s):  
Qingyuan Fang
Keyword(s):  
Temperature Field ◽  
Heat Generation ◽  
Lithium Battery ◽  
Heat Dissipation ◽  
Lithium Ion ◽  
Catalytic Performance ◽  
Performance Model ◽  
Battery Pack ◽  
Discharge Process ◽  
Battery Cell

Abstract Aiming at the uneven heat generation in various parts of the electric vehicle lithium battery pack during the discharge process, the heat generation mechanism is studied, and the lithium battery catalytic performance model is established to obtain the current density and heat generation rate distribution law of the lithium battery cell on the cell. The thermal model can simulate the thermal behavior of the battery under application conditions. Study the laws of battery heat production, heat transfer, and heat dissipation, and calculate the temperature changes inside and on the battery and the temperature field information in real time to provide a basis for the design and optimization of the battery and battery pack thermal management system. The simulation results show that the established model can predict the heating distribution and temperature field of the internal layered structure of the lithium-ion battery, which is helpful for the subsequent analysis of key influencing factors.

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