The effect of energetically coated ZrOx on enhanced electrochemical performances of Li(Ni1/3Co1/3Mn1/3)O2 cathodes using modified radio frequency (RF) sputteringElectronic supplementary information (ESI) available: Configuration of all-solid-state cells, potential profiles as a function of C-rate, results of GITT, potential profiles and EIS data of solid cells, and comparison of cycling performances of liquid/solid-electrolyte-based cells. See DOI: 10.1039/c5ta02055g

• Main Authors: Lee, Ji-Hoon, Kim, Ji Woo, Kang, Ho-Young, Kim, Seul Cham, Han, Sang Sub, Oh, Kyu Hwan, Lee, Se-Hee, Joo, Young-Chang
• Format: Journal Article
• Language: English
• Published: 09.06.2015
• ISSN: 2050-7488; 2050-7496
• DOI: 10.1039/c5ta02055g

To date, most coating layers for electrode materials for Li-ion batteries have been fabricated using the sol-gel method or atomic layer deposition (ALD), which involve complicated processing steps and limited candidates for coating materials. With an emphasis on solving these issues, herein, a new coating methodology based on a sputtering system was developed, and sputtered zirconium oxide was coated on Li(Ni 1/3 Co 1/3 Mn 1/3 )O 2 (L333) cathode powders. The continuous movement of the cathode powders during the coating procedure and the high kinetic energy from the sputtering process resulted in a highly uniform coating layer with multiple structures exhibiting a concentration and valence state gradient of Zr, i.e. , surface (mainly Zr 4+ ) and doped (mainly Zr 2+ ) layers. The ZrO x -coated L333 powders exhibited an outstanding capacity retention (96.3% at the 200th cycle) and superior rate capability compared with the uncoated version in a coin cell with 1 M LiPF 6 in EC : DEC liquid electrolyte. The ZrO x -coated L333 powders also exhibited an enhanced specific capacity in a solid state battery cell with a sulfide-based inorganic solid-state electrolyte. The improved electrochemical performance of ZrO x /L333 was attributed to the synergetic effect from the surface and doped layers: physical/chemical protection of the active material surface, enhancement of Li-ion diffusion kinetics, and stabilization of the interfaces. By introducing the ZrO x layer coated using a novel sputtering, the electrochemical performance of Li(Ni 1/3 Co 1/3 Mn 1/3 )O 2 under liquid and solid electrolyte was greatly improved.