Experimental study of NCM-si batteries with bi-directional actuation

Shuhua Shan, Cody Gonzalez, Christopher Rahn, Mary Frecker

Research output: Chapter in Book/Report/Conference proceedingConference contribution

1 Scopus citations

Abstract

Silicon is regarded as one of the most promising anode materials for lithium-ion batteries. Its high theoretical capacity (4000 mAh/g) has the potential to meet the demands of highenergy density applications, such as electric air and ground vehicles. The volume expansion of Si during lithiation is over 300%, indicating its promise as a large strain electrochemical actuator. A Si-anode battery is multifunctional, storing electrical energy and actuating through volume change by lithium-ion insertion. To utilize the property of large volume expansion, we design, fabricate, and test two types of Si anode cantilevers with bi-directional actuation: (a) bimorph actuator and (b) insulated double unimorph actuator. A transparent battery chamber is fabricated, provided with NCM cathodes, and filled with electrolyte. The relationship between state of charge and electrode deformation is measured using current integration and high-resolution photogrammetry, respectively. The electrochemical performance, including voltage versus capacity and Coulombic efficiency versus cycle number, is measured for several charge/discharge cycles. Both configurations exhibit deflections in two directions and can store energy. In case (a), the largest deflection is roughly 35% of the cantilever length. Twisting and unexpected bending deflections are observed in this case, possibly due to back-side lithiation, non-uniform coating thickness, and uneven lithium distribution. In case (b), the single silicon active coating layer can deflect 12 passive layers.

Original languageEnglish (US)
Title of host publicationProceedings of ASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2021
PublisherAmerican Society of Mechanical Engineers (ASME)
ISBN (Electronic)9780791885499
DOIs
StatePublished - 2021
EventASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2021 - Virtual, Online
Duration: Sep 14 2021Sep 15 2021

Publication series

NameProceedings of ASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2021

Conference

ConferenceASME 2021 Conference on Smart Materials, Adaptive Structures and Intelligent Systems, SMASIS 2021
CityVirtual, Online
Period9/14/219/15/21

All Science Journal Classification (ASJC) codes

  • Civil and Structural Engineering
  • Mechanics of Materials
  • Artificial Intelligence

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