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All‐Solid‐State Lithium‐Ion Microbatteries Using Silicon Nanofilm Anodes: High Performance and Memory Effect
Author(s) -
Cras Frédéric Le,
Pecquenard Brigitte,
Dubois Vincent,
Phan VietPhong,
GuyBouyssou Delphine
Publication year - 2015
Publication title -
advanced energy materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 10.08
H-Index - 220
eISSN - 1614-6840
pISSN - 1614-6832
DOI - 10.1002/aenm.201501061
Subject(s) - materials science , anode , lithium (medication) , silicon , electrolyte , optoelectronics , electrochemistry , microelectronics , amorphous solid , electrode , nanotechnology , chemistry , medicine , organic chemistry , endocrinology
All‐solid‐state thin film lithium batteries are promising devices to power the next generations of autonomous microsystems. Nevertheless, some industrial constraints such as the resistance to reflow soldering (260 °C) and to short‐circuiting necessitate the replacement of the lithium anode. In this study, a 2 V lithium‐ion system based on amorphous silicon nanofilm anodes (50–200 nm thick), a LiPON electrolyte, and a new lithiated titanium oxysulfide cathode Li 1.2 TiO 0.5 S 2.1 is prepared by sputtering. The determination of the electrochemical behavior of each active material and of whole systems with different configurations allows the highlighting of the particular behavior of the Li x Si electrode and the understanding of its consequences on the performance of Li‐ion cells. Lithium‐ion microbatteries processed with industrial tools and embedded in microelectronic packages exhibit particularly high cycle life (−0.006% cycle −1 ), ultrafast charge (80% capacity in 1 min), and tolerate both short‐circuiting and reflow soldering. Moreover, the perfect stability of the system allows the assignment of some modifications of the voltage curve and a slow and reversible capacity fade occurring in specific conditions, to the formation of Li 15 Si 4 and to the expression of a “memory effect.” These new findings will help to optimize the design of future Li‐ion systems using nanosized silicon anodes.