Direct-Write Lithiation of Silicon Using a Focused Ion Beam of Li .

Autor: McGehee WR; National Institute of Standards and Technology , Gaithersburg , Maryland 20899 , United States., Strelcov E; National Institute of Standards and Technology , Gaithersburg , Maryland 20899 , United States.; Maryland NanoCenter , University of Maryland , College Park , Maryland 20742 , United States., Oleshko VP; National Institute of Standards and Technology , Gaithersburg , Maryland 20899 , United States., Soles C; National Institute of Standards and Technology , Gaithersburg , Maryland 20899 , United States., Zhitenev NB; National Institute of Standards and Technology , Gaithersburg , Maryland 20899 , United States., McClelland JJ; National Institute of Standards and Technology , Gaithersburg , Maryland 20899 , United States.
Jazyk: angličtina
Zdroj: ACS nano [ACS Nano] 2019 Jul 23; Vol. 13 (7), pp. 8012-8022. Date of Electronic Publication: 2019 Jul 10.
DOI: 10.1021/acsnano.9b02766
Abstrakt: Electrochemical processes that govern the performance of lithium ion batteries involve numerous parallel reactions and interfacial phenomena that complicate the microscopic understanding of these systems. To study the behavior of ion transport and reaction in these applications, we report the use of a focused ion beam of Li + to locally insert controlled quantities of lithium with high spatial resolution into electrochemically relevant materials in vacuo . To benchmark the technique, we present results on direct-write lithiation of 35 nm thick crystalline silicon membranes using a 2 keV beam of Li + at doses up to 10 18 cm -2 (10 4 nm -2 ). We confirm quantitative sub-μm control of lithium insertion and characterize the concomitant morphological, structural, and functional changes of the system using a combination of electron and scanning probe microscopy. We observe saturation of interstitial lithium in the silicon membrane at ≈10% dopant number density and spillover of excess lithium onto the membrane's surface. The implanted Li + is demonstrated to remain electrochemically active. This technique will enable controlled studies and improve understanding of Li + ion interaction with local defect structures and interfaces in electrode and solid-electrolyte materials.
Databáze: MEDLINE