The instability of Nickel (Ni)‐rich cathodes at high voltage is a critical bottleneck toward developing superior lithium‐ion batteries. This instability is driven by cathode‐electrolyte side reactions, causing rapid degradation, and compromising the overall cycle life. In this study, a protective coating using dispersed “magnetite (FeO.Fe2O3)” nanoparticles is used to uniformly decorate the surface of LiNi0.8Co0.1Mn0.1O2(NMC 811) microparticles. The modified cathode delivers significant improvement in electrochemical performance at high voltage (≈4.6 V) by suppressing deleterious electrode–electrolyte interactions. A notably higher cycle stability, rate performance, and overall energy density is realized for the coated cathode in a conventional liquid electrolyte battery. When deployed in pellet‐stacked solid‐state cells with Li6PS5Cl as the electrolyte, the magnetite‐coated NMC 811 showed strikingly superior cycling stability than its uncoated counterpart, proving the versatility of the chemistry. The facile surfactant‐assisted coating process developed in this work, in conjunction with the affordability, abundance, and nontoxic nature of magnetite makes this a promising approach to realize commercially viable high voltage Ni‐rich cathodes that exhibit stable performance in liquid as well as solid‐state lithium‐ion batteries.
Improved performance of lithium-ion batteries (LIBs) plays a critical role in the future of next- generation battery applications. Nickel-rich layered oxides such as LiNi0.8Mn0.1Co0.1O2(NMC 811), are popular cathodes due to their high energy densities. However, they suffer from high surface reactivity, which results in the formation of Li2CO3passive layer. Herein, we show the role of nanosecond pulsed laser annealing (PLA) in improving the current capacity and cycling stability of LIBs by reducing the carbonate layer, in addition to forming a protective LiF layer and manipulating the NMC 811 microstructures. We use high-power nanosecond laser pulses in a controlled way to create nanostructured surface topography which has a positive impact on the capacity retention and current capacity by providing an increased active surface area, which influences the diffusion kinetics of lithium-ions in the electrode materials during the battery cycling process. Advanced characterizations show that the PLA treatment results in the thinning of the passive Li2CO3layer, which is formed on as-received NMC811 samples, along with the decomposition of excess polyvinylidene fluoride (PVDF) binder. The high-power laser interacts with the decomposed binder and surface Li+to form LiF phase, which acts as a protective layer to prevent surface reactive sites from initiating parasitic reactions. As a result, the laser treated cathodes show relative increase of the current capacity of up to 50%, which is consistent with electrochemical measurements of LiB cells.
more » « less- NSF-PAR ID:
- 10402147
- Publisher / Repository:
- The Electrochemical Society
- Date Published:
- Journal Name:
- Journal of The Electrochemical Society
- Volume:
- 170
- Issue:
- 3
- ISSN:
- 0013-4651
- Page Range / eLocation ID:
- Article No. 030520
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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