Origins and accommodation of cell variations in Li‐ion battery pack modeling

Rechargeable battery industry will see significant growth in the use of battery systems for portable devices and power electronics, renewable energy storage, power systems for transportation, and telecom backup power applications. Despite such promising market sentiment, the battery system management remains as a challenging issue to be resolved in order to provide a safe and reliable power and energy storage system. Here we report advancement in the battery management approach by providing a solution to analyze battery performance variations in a lot of batteries produced from the same manufacturing process. A lot of 100 Li-ion cells were analyzed in order to quantify the inherent cell variations associated with cell manufacturing process and test protocol. Both statistical and electrochemical analyses were used to characterize and quantify the capacity variations among the cells along with other parameters that can be readily derived from the test results. Information extracted from a minimal testing of the cells in the lot and more intensive characterizations on a few cells including one as the nominal sample cell allows the establishment of a single cell model (SCM), based on a generic equivalent circuit, with high accuracy in predicting cell performance. The analyses also permit a carefully crafted logic development of how to separate the origins that cause the cell variations in performance. Such separation of the attributes enable a proper tuning of the cell parameters in the model, which allows the accommodation of cell variations in a battery pack model to handle most of the imbalance issues. A careful validation of the SCM to predict performance of any arbitrary cell in the lot with high accuracy was demonstrated. Copyright © 2009 John Wiley & Sons, Ltd.

[1]  Dominique Guyomard,et al.  New Composite Electrode Architecture and Improved Battery Performance from the Smart Use of Polymers and Their Properties , 2004 .

[2]  Robert Dominko,et al.  Influence of carbon black distribution on performance of oxide cathodes for Li ion batteries , 2003 .

[3]  Ralph E. White,et al.  Development of First Principles Capacity Fade Model for Li-Ion Cells , 2004 .

[4]  C. Delmas,et al.  Lithium Electrochemical Deintercalation from O 2 ­ LiCoO2 Structure and Physical Properties , 2002 .

[5]  Vojtech Svoboda,et al.  Capacity and power fading mechanism identification from a commercial cell evaluation , 2007 .

[6]  Gregory L. Plett,et al.  Sigma-point Kalman filtering for battery management systems of LiPB-based HEV battery packs Part 2: Simultaneous state and parameter estimation , 2006 .

[7]  Greg Meyers,et al.  Composite Cathode Structure/Property Relationships , 2007, ECS Transactions.

[8]  R. Spotnitz.  Simulation of capacity fade in lithium-ion batteries , 2003 .

[9]  Ralph E. White,et al.  A non-isothermal model of a nickel–metal hydride cell , 2001 .

[10]  J. Barker,et al.  Differential capacity as a spectroscopic probe for the investigation of alkali metal insertion reactions , 1996 .

[11]  Young Soo Yoon,et al.  Particle size effects on temperature-dependent performance of LiCoO2 in lithium batteries , 2006 .

[12]  John Newman,et al.  High-power batteries for use in hybrid vehicles , 2000 .

[13]  Matthieu Dubarry,et al.  From single cell model to battery pack simulation for Li-ion batteries , 2009 .

[14]  M. Dubarry,et al.  Incremental Capacity Analysis and Close-to-Equilibrium OCV Measurements to Quantify Capacity Fade in Commercial Rechargeable Lithium Batteries , 2006 .

[15]  E. Barsoukov,et al.  Kinetics of lithium intercalation into carbon anodes: in situ impedance investigation of thickness and potential dependence , 1999 .

[16]  Ganesan Nagasubramanian,et al.  Modeling capacity fade in lithium-ion cells , 2005 .

[17]  J. Barker,et al.  Three Electrode Electrochemical Voltage Spectroscopy (TEVS): evaluation of a model lithium ion system , 1995 .

[18]  Matthieu Dubarry,et al.  Development of a universal modeling tool for rechargeable lithium batteries , 2007 .

[19]  Bor Yann Liaw,et al.  Integrated battery simulation and characterization , 2002 .

[20]  Matthieu Dubarry,et al.  From Li-ion single cell model to battery pack simulation , 2008, 2008 IEEE International Conference on Control Applications.

[21]  J. Dahn,et al.  Electrochemical and In Situ X‐Ray Diffraction Studies of Lithium Intercalation in Li x CoO2 , 1992 .

[22]  J. Barker,et al.  An electrochemical investigation into the lithium insertion properties of LixNiO2 (0 ≤ x ≤ 1) , 1996 .

[23]  Vojtech Svoboda,et al.  Capacity loss in rechargeable lithium cells during cycle life testing: The importance of determining state-of-charge , 2007 .