| 1. |
- Armand, Michel, et al.
(författare)
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Lithium-ion batteries – Current state of the art and anticipated developments
- 2020
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Ingår i: Journal of Power Sources. - : Elsevier BV. - 0378-7753 .- 1873-2755. ; 479
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Tidskriftsartikel (refereegranskat)abstract
- Lithium-ion batteries are the state-of-the-art electrochemical energy storage technology for mobile electronic devices and electric vehicles. Accordingly, they have attracted a continuously increasing interest in academia and industry, which has led to a steady improvement in energy and power density, while the costs have decreased at even faster pace. Important questions, though, are, to which extent and how (fast) the performance can be further improved, and how the envisioned goal of truly sustainable energy storage can be realized. Herein, we combine a comprehensive review of important findings and developments in this field that have enabled their tremendous success with an overview of very recent trends concerning the active materials for the negative and positive electrode as well as the electrolyte. Moreover, we critically discuss current and anticipated electrode fabrication processes, as well as an essential prerequisite for “greener” batteries – the recycling. In each of these chapters, we eventually summarize important remaining challenges and propose potential directions for further improvement. Finally, we conclude this article with a brief summary of the performance metrics of commercial lithium-ion cells and a few thoughts towards the future development of this technology including several key performance indicators for the mid-term to long-term future.
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| 2. |
- Jeschull, Fabian, et al.
(författare)
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Interphase formation with carboxylic acids as slurry additives for Si electrodes in Li-ion batteries. Part 1 : performance and gas evolution
- 2023
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Ingår i: Journal of Physics. - : Institute of Physics Publishing (IOPP). - 2515-7655. ; 5:2
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Tidskriftsartikel (refereegranskat)abstract
- Rendering the solid electrolyte interphase and the inter-particle connections more resilient to volume changes of the active material is a key challenge for silicon electrodes. The slurry preparation in a buffered aqueous solution offers a strategy to increase the cycle life and capacity retention of silicon electrodes considerably. So far, studies have mostly been focused on a citrate buffer at pH = 3, and therefore, in this study a series of carboxylic acids is examined as potential buffers for slurry preparation in order to assess which chemical and physical properties of carboxylic acids are decisive for maximizing the capacity retention for Si as active material. In addition, the cycling stability of buffer-containing electrodes was tested in dependence of the buffer content. The results were complemented by analysis of the gas evolution using online electrochemical mass spectrometry in order to understand the SEI layer formation in presence of carboxylic acids and effect of high proton concentration.
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| 5. |
- Yin, Wei, et al.
(författare)
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Structural evolution at the oxidative and reductive limits in the first electrochemical cycle of Li1.2Ni0.13Mn0.54Co0.13O2
- 2020
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 11:1
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Tidskriftsartikel (refereegranskat)abstract
- High-energy-density lithium-rich materials are of significant interest for advanced lithium-ion batteries, provided that several roadblocks, such as voltage fade and poor energy efficiency are removed. However, this remains challenging as their functioning mechanisms during first cycle are not fully understood. Here we enlarge the cycling potential window for Li1.2Ni0.13Mn0.54Co0.13O2 electrode, identifying novel structural evolution mechanism involving a structurally-densified single-phase A’ formed under harsh oxidizing conditions throughout the crystallites and not only at the surface, in contrast to previous beliefs. We also recover a majority of first-cycle capacity loss by applying a constant-voltage step on discharge. Using highly reducing conditions we obtain additional capacity via a new low-potential P” phase, which is involved into triggering oxygen redox on charge. Altogether, these results provide deeper insights into the structural-composition evolution of Li1.2Ni0.13Mn0.54Co0.13O2 and will help to find measures to cure voltage fade and improve energy efficiency in this class of material.
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| 6. |
- Zhang, Leiting, et al.
(författare)
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Elucidating the Humidity-Induced Degradation of Ni-Rich Layered Cathodes for Li-Ion Batteries
- 2022
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Ingår i: ACS Applied Materials and Interfaces. - : American Chemical Society (ACS). - 1944-8244 .- 1944-8252. ; 14:11, s. 13240-13249
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Tidskriftsartikel (refereegranskat)abstract
- Ni-rich layered oxides, in a general term of Li(NixCoyMn1–x–y)O2 (x > 0.5), are widely recognized as promising candidates for improving the specific energy and lowering the cost for next-generation Li-ion batteries. However, the high surface reactivity of these materials results in side reactions during improper storage and notable gas release when the cell is charged beyond 4.3 V vs Li+/Li0. Therefore, in this study, we embark on a comprehensive investigation on the moisture sensitivity of LiNi0.85Co0.1Mn0.05O2 by aging it in a controlled environment at a constant room-temperature relative humidity of 63% up to 1 year. We quantitatively analyze the gassing of the aged samples by online electrochemical mass spectrometry and further depict plausible reaction pathways, accounting for the origin of the gas release. Transmission electron microscopy reveals formation of an amorphous surface impurity layer of ca. 10 nm in thickness, as a result of continuous reactions with moisture and CO2 from the air. Underneath it, there is another reconstructed layer of ca. 20 nm in thickness, showing rock salt/spinel-like features. Our results provide insight into the complex interfacial degradation phenomena and future directions for the development of high-performance Ni-rich layered oxides.
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| 7. |
- Zhang, Leiting, et al.
(författare)
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Unraveling gas evolution in sodium batteries by online electrochemical mass spectrometry
- 2021
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Ingår i: Energy Storage Materials. - : Elsevier. - 2405-8289 .- 2405-8297. ; 42, s. 12-21
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Tidskriftsartikel (refereegranskat)abstract
- Identification of gaseous decomposition products from irreversible side-reactions enables understanding of inner working of rechargeable batteries. Unlike for Li-ion batteries, the knowledge of the gas-evolution processes in Na-ion batteries is limited. Therefore, in this study, we have performed online electrochemical mass spectrometry to understand gassing behavior of model electrodes and electrolytes in Na-ion cells. Our results show that a less stable solid-electrolyte interphase (SEI) layer is developed in Na-ion cells as compared with that in Li-ion cells, which is mainly caused by higher solubility of SEI constituents in Na-electrolytes. Electrolyte reduction on the anode has much larger contribution to the gassing in the Na-ion cells, as gas evolution comes not only from direct electrolyte reduction but also from the soluble species, which migrate to the cathode and are decomposed there. During cell cycling, linear carbonates do not form an SEI layer on the anode, resulting in continuous electrolyte reduction, similar to Li-ion system but with much higher severity, while cyclic carbonates form a more stable SEI, preventing further decomposition of the electrolyte. Besides the standard electrolyte solvents, we have also assessed effects of several common electrolyte additives in their ability to stabilize the interphases. The results of this study provide understanding and guidelines for developing more durable electrode-electrolyte interphase, enabling higher specific energy and improved cycling stability for Na-ion batteries.
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