A Novel Composite Equalizer Based on an Additional Cell for Series-Connected Lithium-Ion Cells

Cell inconsistency can lead to poor performance and safety hazards. Therefore, cell equalizer is essentially required to prevent the series-connected cells from overcharging, undercharging, and overdischarging. Among current equalization schemes, passive equalizer has a continuously wasting energy with low equalization efficiency, and active equalizer has high cost with complex circuit structure. In this study, a novel composite equalizer based on an additional cell with low complexity is presented. This method combines a passive equalizer and an active equalizer. Firstly, the configuration and circuit of our proposed composite equalizer are introduced, and the equalization principle is analyzed. On this basis, the control strategy and algorithm of the composite equalizer are further proposed. Finally, the composite equalizer is verified through simulation and experiment in various cases. The study results show that this method improves both the consistency level and the available capacity of the battery pack. Moreover, our proposed equalizer can overcome the shortcomings of commonly used equalizer and combining the advantages of different equalizer to maximize the equalization efficiency with a simpler equalizer structure.

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Evaluation of Saft Ultra High Power Lithium Ion Cells (VL5U)

10.21236/ada494956 ◽

2009 ◽

Cited By ~ 3

Author(s):

Jan L. Allen ◽

Jeff Wolfenstine ◽

Kang Xu ◽

Donald Porschet ◽

Thomas Salem ◽

...

Keyword(s):

High Power ◽

Lithium Ion ◽

Lithium Ion Cells

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Advances of 2nd Life Applications for Lithium Ion Batteries from Electric Vehicles Based on Energy Demand

Sustainability ◽

10.3390/su13105726 ◽

2021 ◽

Vol 13 (10) ◽

pp. 5726

Author(s):

Aleksandra Wewer ◽

Pinar Bilge ◽

Franz Dietrich

Keyword(s):

Life Cycle ◽

Lithium Ion Batteries ◽

Electric Vehicles ◽

Energy Demand ◽

Lithium Ion ◽

Life Cycles ◽

Future Research ◽

Research Areas ◽

Study Results ◽

The Impact

Electromobility is a new approach to the reduction of CO2 emissions and the deceleration of global warming. Its environmental impacts are often compared to traditional mobility solutions based on gasoline or diesel engines. The comparison pertains mostly to the single life cycle of a battery. The impact of multiple life cycles remains an important, and yet unanswered, question. The aim of this paper is to demonstrate advances of 2nd life applications for lithium ion batteries from electric vehicles based on their energy demand. Therefore, it highlights the limitations of a conventional life cycle analysis (LCA) and presents a supplementary method of analysis by providing the design and results of a meta study on the environmental impact of lithium ion batteries. The study focuses on energy demand, and investigates its total impact for different cases considering 2nd life applications such as (C1) material recycling, (C2) repurposing and (C3) reuse. Required reprocessing methods such as remanufacturing of batteries lie at the basis of these 2nd life applications. Batteries are used in their 2nd lives for stationary energy storage (C2, repurpose) and electric vehicles (C3, reuse). The study results confirm that both of these 2nd life applications require less energy than the recycling of batteries at the end of their first life and the production of new batteries. The paper concludes by identifying future research areas in order to generate precise forecasts for 2nd life applications and their industrial dissemination.

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