A polymerized C60 coating enhancing interfacial stability at three-dimensional LiCoO2 in high-potential regime

The interfacial instabilities, including side reactions due to electrolyte decompositions and Cobalt (Co) dissolutions, are the main detrimental processes at LiCoO2 cathode when a high-voltage window (>4.2 V) is applied. Nevertheless, cycling the cathode with a voltage above 4.2 V would deliver a...

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Bibliographic Details
Published in:	Journal of power sources 2015-12, Vol.298, p.1-7
Main Authors:	Hudaya, Chairul, Halim, Martin, Pröll, Johannes, Besser, Heino, Choi, Wonchang, Pfleging, Wilhelm, Seifert, Hans Jürgen, Lee, Joong Kee
Format:	Article
Language:	eng
Subjects:	Co dissolutions High-voltage window Interfacial kinetics Laser structuring/annealing Polymerized C60 coating films Three-dimensional LiCoO2
Online Access:	Get full text
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Summary:	The interfacial instabilities, including side reactions due to electrolyte decompositions and Cobalt (Co) dissolutions, are the main detrimental processes at LiCoO2 cathode when a high-voltage window (>4.2 V) is applied. Nevertheless, cycling the cathode with a voltage above 4.2 V would deliver an increased gravimetric capacity, which is desired for high power battery operation. To address these drawbacks, we demonstrate a synergistic approach by manufacturing the three-dimensional high-temperature LiCoO2 electrodes (3D HT-LCO) using laser-microstructuring, laser-annealing and subsequent coating with polymerized C60 thin films (C60@3D HT-LCO) by plasma-assisted thermal evaporation. The C60@3D HT-LCO cathode delivers higher initial discharge capacity compared to its theoretical value, i.e. 175 mA h g−1 at 0.1 C with cut-off voltage of 3.0–4.5 V. This cathode combines the advantages of the 3D electrode architecture and an advanced C60 coating/passivation concept leading to an improved electrochemical performance, due to an increased active surface area, a decreased charge transfer resistance, a prevented Co dissolution into the electrolyte and a suppressed side reaction and electrolyte decomposition. This work provides a novel solution for other cathode materials having similar concerns in high potential regimes for application in lithium-ion microbatteries. [Display omitted] •3D high-temperature LiCoO2 (3D HT-LCO) is realized by laser structuring/annealing.•3D design enables higher surface area for electrolyte access and Li+ diffusions.•C60@3D HT-LCO delivers initial discharge capacity of 175 mAhg−1 at 0.1 C (3.0–4.5 V).•3D architecture and polymerized C60 coating decrease the charge transfer resistance.•Polymerized C60 coating prevents Co dissolutions and suppress side reactions.
ISSN:	0378-7753 1873-2755