Powering the Digital Revolution: A Miniaturized Lithium Battery Made of Single-Crystalline Silicon

Michael Sternad, Magdalena Forster, Martin Wilkening

Research output: Contribution to conferencePosterResearch

Abstract

Single-crystalline Si represents not only the material that allows the realization of monolithic integrated circuits, it also possesses outstanding lithium uptake capabilities. In contrast to the most common anode materials for which lithiation proceeds according to topotactic insertion as well as transformation mechanisms, the reaction of lithium with silicon is different: a “ledge-mechanism” is present which means Si layer after Si-layer is peeled off [1]. During lithiation the silicon which is detached transforms to an amorphous LixSi-phase [2, 3] with fast Li-ion diffusivity [4]; the Si-layers located far from the surface remain untouched and, thus, mechanically resilient.
Under these conditions and because of the lithiation mechanism, highly doped single-crystalline silicon may perform two specific functions in a battery integrated on a chip: (i) as both current collector and housing material and (ii) as powerful anode material with a maximum charge density of 3579 mAhg-1, which is electrochemically accessible [2].
In the present work a novel μ-battery with an anode and a case of highly doped semiconductor-grade single crystalline silicon, a liquid electrolyte and an NCA-cathode is introduced. The battery can be placed on the free silicon backside of a microchip. While SEM/FIB-measurements were used to characterize the morphological changes of the material, the electrochemical performance of the system was thoroughly studied. The battery as it is now shows excellent cycling performance: it can be cycled for more than hundred times at specific anode charge densities as high as 1000 mAhg-1 and coulombic efficiencies better than 99,8 %.
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Original languageEnglish
Publication statusPublished - 21 Jun 2016
Event18th International Meeting on Lithium Batteries - Hyatt Regency Chicago, Chicago, IL, United States
Duration: 19 Jun 201624 Jun 2016

Conference

Conference18th International Meeting on Lithium Batteries
CountryUnited States
CityChicago, IL
Period19/06/1624/06/16

Fields of Expertise

  • Advanced Materials Science

Cite this

Sternad, M., Forster, M., & Wilkening, M. (2016). Powering the Digital Revolution: A Miniaturized Lithium Battery Made of Single-Crystalline Silicon. Poster session presented at 18th International Meeting on Lithium Batteries, Chicago, IL, United States.