Enhancement of Ultrahigh Rate Chargeability by Interfacial Nanodot BaTiO₃ Treatment on LiCoO₂ Cathode Thin Film Batteries

Abstract

Nanodot BaTiO 3 supported LiCoO 2 cathode thin films can dramatically improve high-rate chargeability and cyclability. The prepared BaTiO 3 nanodot is <3 nm in height and 35 nm in diameter, and its coverage is <5%. Supported by high dielectric constant materials on the surface of cathode materials, Li ion (Li + ) can intercalate through robust Li paths around the triple-phase interface consisting of the dielectric, cathode, and electrolyte. The current concentration around the triple-phase interface is observed by the finite element method and is in good agreement with the experimental data. The interfacial resistance between the cathode and electrolyte with nanodot BaTiO 3 is smaller than that without nanodot BaTiO 3 . The decomposition of the organic solvent electrolyte can prevent the fabrication of a solid electrolyte interface around the triple-phase interface. Li + paths may be created at non solid electrolyte interface covered regions by the strong current concentration originating from high dielectric constant materials on the cathode. Robust Li + paths lead to excellent chargeability and cyclability.

In-situ visualization of the space-charge-layer effect on interfacial lithium-ion transport in all-solid-state batteries

“…The SCL formation is an interfacial charge redistribution process driven by the chemical potential difference between the cathode and electrolyte, which should also be influenced by an electric field. Thus, introducing a built-in electric field at the cathode/electrolyte interface will suppress the SCL formation and even create lithium-ion conduction pathways by adjusting the interface charge redistribution at the TPI without adding an additional interfacial diffusion barrier 40,[49][50][51][52][53][54] . Dielectric materials have been demonstrated to build an internal electric field under an external electric field, stress, or temperature.…”

“…The internal electric field mappings at the LCO/ LPSCl and BTO-LCO/LPSCl interfaces are calculated through FEM simulations based on the semiconductor analogy (Supplementary Fig. 13) 44,50,55,56 . As shown in Fig.…”

An Overview on the Advances of LiCoO2 Cathodes for Lithium‐Ion Batteries

“…Cho et al triggered to coat Al 2 O 3 , LiMn 2 O 4 , and ZrO 2 on the surface of LiCoO 2 . [ 105 ] After that, various oxides such as TiO 2 , [ 106 ] ZnO, [ 107 ] B 2 O 3 , [ 108 ] Li 4 Ti 5 O 12 , [ 109 ] ZrO 2 , [ 110 ] BaTiO 3 , [ 111 ] metal fluoride, [ 112 ] and phosphate [ 113 ] were tried as coating layers to protect the electrode. However, the mechanism of surface coating has not been fully understood as of today.…”

Enhanced Cycling and Rate Capability by Epitaxially Matched Conductive Cubic TiO Coating on LiCoO2 Cathode Films

“…Many thin-film studies have investigated the effect of an additional amorphous or polycrystalline coating; however, only a few studies have explored the impact of an epitaxially matched layer (ZrO 2 , BaTiO 3 ) on the surface of a highly crystalline LiCoO 2 thin film. 24 , 48 Therefore, a large knowledge gap currently exists in how the alignment of the crystal structures across such epitaxial coating–cathode interface can enhance lithium transport while preventing parasitic reactions with the adjacent electrolyte.…”