A nano-LiNbO₃ coating layer and diffusion-induced surface control towards high-performance 5 V spinel cathodes for rechargeable batteries

Abstract

The surface of a spinel LiNi0.5Mn1.5O4 cathode was modified with a nano-LiNbO3 coating layer by employing a Nb citrate-coated Ni0.25Mn0.75(OH)2 precursor and subsequent single calcination with LiOH at 900 °C.

Enhancing the Stability of LiNi0.5Mn1.5O4 by Coating with LiNbO3 Solid-State Electrolyte: Novel Chemically Activated Coating Process versus Sol-Gel Method

“…It is important to mention, that during the temperature treatment, especially at 800 °C, doping with niobium cations of the LNMO spinel could take place for the cations at the lithium and/or the Mn/Ni positions. Comparable substitutions have already been observed (e.g., for Ti, Al, Mg and Nb) and become evident on the basis of changed lattice parameter of LNMO [ 13 , 20 , 31 , 32 , 33 , 34 , 35 ]. Nb ions generally exhibit an oxidation state 5+ and have a similar ionic radius with Mn ions in the octahedral coordination environment.…”

“…The coating of cathode materials with Li/Nb-containing compounds is well documented in the literature [ 18 , 19 , 20 ]. The key methods for obtaining such coatings are solid state reactions [ 18 ] and sol-gel methods [ 19 ].…”

Enhanced Electrochemical Properties of All-Solid-State Batteries Using a Surface-Modified LiNi0.6Co0.2Mn0.2O2 Cathode

“…The coated precursors were then calcined with a lithium source to form the cathode (LiNi 0.6 Co 0.2 Mn 0.2 O 2) and coating layer (Li-Zr-O and Li-Mo-O). During this process, cation migration (or doping) from the coating sources may occur, which enhances the binding between the surface layer and parent cathode [36,37]. In addition, the surface layer of the cathode is also more homogeneous than the post-coating route.…”

Neutron reflectometry to measure in situ the rate determining step of lithium ion transport through thin silicon layers and interfaces

“…On the positive electrode side, thin LiNbO 3 layers inserted between the electrolyte and the positive electrode were found to be beneficial for LIB operation. [14][15][16][17][18][19][20][21][22][23] The interface between these two materials is also of interest because LiNbO 3 adjacent to silicon thin layers might be important for the fabrication of self-charging LIBs that hybridize mechanical energy harvesting and ion storage processes into one process. 24,25 In general, the reduction of the interface impedance is a challenge for proper all-solid state LIB operation.…”