Artificial cathode electrolyte interphase for improving high voltage cycling stability of thick electrode with Co-free 5 V spinel oxides

High-voltage spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) is a promising nextgeneration cathode material due to its structural stability, high operation voltage, and low cost. However, the cycle life of LNMO cells is compromised by detrimental electrode−electrolyte reactions, chemical crossover, and rapid anode degradation. Here, we demonstrate that the cycling stability of LNMO can be effectively enhanced by a high-energy laser treatment. Advanced characterizations unveil that the laser treatment induces partial decomposition of the polyvinylidene fluoride binder and formation of a surface LiF phase, which mitigates electrode−electrolyte side reactions and reduces the generation of dissolved transition-metal ions and acidic crossover species. As a result, the solid electrolyte interphase of the graphite counter electrode is thin and is composed of fewer electrolyte decomposition products. This work demonstrates the potential of laser treatment in tuning the surface chemistry of cathode materials for lithium-ion batteries.

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Laser-Assisted Surface Lithium Fluoride Decoration of a Cobalt-Free High-Voltage Spinel LiNi_0.5Mn_1.5O₄ Cathode for Long-Life Lithium-Ion Batteries

Cui

Khosla

Lai

et al. 2022

“…Specifically, the R sf values of LNMO@LSO-1 increase slowly from 27.09 Ω after 50 cycles to 42.10 Ω after 200 cycles, while those of LNMO increase sharply from 37.72 Ω after 50 cycles to 122.50 Ω after 200 cycles. The side reaction products, such as LiF, are soluble in the presence of HF, making the CEI layer very unstable, 47 thus leading to the continuous occurrence of side reactions and deposition of side reaction products and then the sharp increase of R sf for LNMO. However, for LNMO@LSO-1, the reaction of Li 2 SiO 3 with HF can prevent the corrosion of the CEI layer by HF, which is helpful to the formation of a stable and dense CEI layer.…”

Section: Resultsmentioning

confidence: 99%

Enhanced Electrochemical Performance of the LiNi_0.5Mn_1.5O₄ Cathode Material by the Construction of Uniform Lithium Silicate Nanoshells

Zhang

et al. 2022

In order to alleviate the rapid capacity decay caused by the instability of the crystal structure and electrode/electrolyte interface, a series of Li 2 SiO 3 -coated LiNi 0.5 Mn 1.5 O 4 materials have been prepared via the lithium acetate-assisted sol−gel method followed by a short-term calcination process. During the sol−gel process, TEOS is hydrolyzed, condensed, and polymerized with the assistance of lithium acetate to form a Li + -embedded [Si−O−Si] n network structure to ensure the uniformity of the coating. By changing the amount of TEOS and lithium acetate, the coating thickness can be precisely controlled, whose effects on the structural and electrochemical properties of LiNi 0.5 Mn 1.5 O 4 materials are intensively investigated. The results show that the material with an appropriate thickness of Li 2 SiO 3 coating exhibits a larger primary particle size and reduced secondary particle agglomeration. The uniform Li 2 SiO 3 coating with appropriate thickness can not only improve Li + ion diffusion kinetics but also suppress side reactions and CEI growth at the electrode/electrolyte interface. Besides, the interaction of Li 2 SiO 3 with HF can alleviate electrode corrosion and the dissolution of transition metal ions. All the abovementioned factors together promote the significant improvement of the electrochemical performance of Li 2 SiO 3 -coated LiNi 0.5 Mn 1.5 O 4 materials.

“…The AlF 3 surface layer as formed protects then the active material from further HF attack. One of the most common techniques used to prepare an Al 2 O 3 coating is the atomic layer deposition (ALD), ,− which allows a fine tuning of the thickness. Nevertheless, up to now, ALD is mainly performed directly on electrodes and not on powders due to difficulties in controlling the formation of a homogeneous coating without any flow (fluidization) of particles.…”

Section: Introductionmentioning

confidence: 99%

Improved Electrochemical Performance for High-Voltage Spinel LiNi_0.5Mn_1.5O₄ Modified by Supercritical Fluid Chemical Deposition

COURBARON

Petit

Serrano-Sevillano

et al. 2023

Among candidates at the positive electrode of the next generation of Liion technology and even beyond post Li-ion technology as all-solid-state batteries, spinel LiNi 0.5 Mn 1.5 O 4 (LNMO) is one of the favorites. Nevertheless, before its integration into commercial systems, challenges still remain to be tackled, especially the stabilization of interfaces with the electrolyte (liquid or solid) at high voltage. In this work, a simple, fast, and cheap process is used to prepare a homogeneous coating of Al 2 O 3 type to modify the surface of the spinel LNMO: the supercritical fluid chemical deposition (SFCD) route. This process is, to the best of our knowledge, used for the first time in the battery field. Significantly improved performance was demonstrated vs those of bare LNMO, especially at high rates and for highly loaded electrodes.