| 1. |
- Cengiz, Elif Ceylan, 1986, et al.
(author)
-
Review - Reference Electrodes in Li-Ion and Next Generation Batteries: Correct Potential Assessment, Applications and Practices
- 2021
-
In: Journal of the Electrochemical Society. - : The Electrochemical Society. - 1945-7111 .- 0013-4651. ; 168:12
-
Research review (peer-reviewed)abstract
- This review provides an accessible analysis of the processes on reference electrodes and their applications in Li-ion and next generation batteries research. It covers fundamentals and definitions as well as specific practical applications and is intended to be comprehensible for researchers in the battery field with diverse backgrounds. It covers fundamental concepts, such as two- and three-electrodes configurations, as well as more complex quasi- or pseudo- reference electrodes. The electrode potential and its dependance on the concentration of species and nature of solvents are explained in detail and supported by relevant examples. The solvent, in particular the cation solvation energy, contribution to the electrode potential is important and a largely unknown issue in most the battery research. This effect can be as high as half a volt for the Li/Li+ couple and we provide concrete examples of the battery systems where this effect must be taken into account. With this review, we aim to provide guidelines for the use and assessment of reference electrodes in the Li-ion and next generation batteries research that are comprehensive and accessible to an audience with a diverse scientific background.
|
|
| 2. |
- Chen, Chih-Yao, et al.
(author)
-
High-voltage honeycomb layered oxide positive electrodes for rechargeable sodium batteries
- 2020
-
In: Chemical Communications. - : Royal Society of Chemistry (RSC). - 1364-548X .- 1359-7345. ; 56:65, s. 9272-9275
-
Journal article (peer-reviewed)abstract
- Honeycomb layered oxides from Na2Ni2-xCoxTeO6 family were assessed for use as positive electrodes in rechargeable sodium batteries at ambient and elevated temperatures using ionic liquids. Substitution of nickel with cobalt increases the discharge voltage to nearly 4 V (versus Na+/Na), surpassing the average voltages of most Na based layered oxide positive electrodes.
|
|
| 3. |
- Kanyolo, Godwill Mbiti, et al.
(author)
-
Honeycomb layered oxides: Structure, energy storage, transport, topology and relevant insights
- 2021
-
In: Chemical Society Reviews. - : Royal Society of Chemistry (RSC). - 1460-4744 .- 0306-0012. ; 50:6, s. 3990-4030
-
Research review (peer-reviewed)abstract
- The advent of nanotechnology has hurtled the discovery and development of nanostructured materials with stellar chemical and physical functionalities in a bid to address issues in energy, environment, telecommunications and healthcare. In this quest, a class of two-dimensional layered materials consisting of alkali or coinage metal atoms sandwiched between slabs exclusively made of transition metal and chalcogen (or pnictogen) atoms arranged in a honeycomb fashion have emerged as materials exhibiting fascinatingly rich crystal chemistry, high-voltage electrochemistry, fast cation diffusion besides playing host to varied exotic electromagnetic and topological phenomena. Currently, with a niche application in energy storage as high-voltage materials, this class of honeycomb layered oxides serves as ideal pedagogical exemplars of the innumerable capabilities of nanomaterials drawing immense interest in multiple fields ranging from materials science, solid-state chemistry, electrochemistry and condensed matter physics. In this review, we delineate the relevant chemistry and physics of honeycomb layered oxides, and discuss their functionalities for tunable electrochemistry, superfast ionic conduction, electromagnetism and topology. Moreover, we elucidate the unexplored albeit vastly promising crystal chemistry space whilst outlining effective ways to identify regions within this compositional space, particularly where interesting electromagnetic and topological properties could be lurking within the aforementioned alkali and coinage-metal honeycomb layered oxide structures. We conclude by pointing towards possible future research directions, particularly the prospective realisation of Kitaev-Heisenberg-Dzyaloshinskii-Moriya interactions with single crystals and Floquet theory in closely-related honeycomb layered oxide materials. This journal is
|
|
| 4. |
- Lacarbonara, Giampaolo, et al.
(author)
-
Operando insights into ammonium-mediated lithium metal stabilization: surface morphology modulation and enhanced SEI development
- 2024
-
In: Journal of Colloid and Interface Science. - 1095-7103 .- 0021-9797. ; 669, s. 699-711
-
Journal article (peer-reviewed)abstract
- Lithium-ion batteries (LiBs) with graphite as an anode and lithiated transition metal oxide as a cathode are approaching their specific energy and power theoretical values. To overcome the limitations of LiBs, lithium metal anode with high specific capacity and low negative redox potential is necessary. However, practical application in rechargeable cells is hindered by uncontrolled lithium deposition manifesting, for instance, as Li dendrite growth which can cause formation of dead Li, short circuits and cell failure. The electrochemical behaviour of a protic additive (NH4PF6) in a carbonate-based electrolyte has been investigated by operando confocal Raman spectroscopy, in situ optical microscopy, and X-ray photoelectron spectroscopy, elucidating its functional mechanism. The ammonium cation promotes a chemical modification of the lithium metal anode-electrolyte interphase by producing an N-rich solid electrolyte interphase and chemically modifying the lithium surface morphology by electrochemical pitting. This novel method results in stable lithium deposition and stripping by a decreasing the local current density on the electrode, thus limiting dendritic deposition.
|
|
| 5. |
- Lee, Suyeong, et al.
(author)
-
High-Energy and Long-Lifespan Potassium–Sulfur Batteries Enabled by Concentrated Electrolyte
- 2022
-
In: Advanced Functional Materials. - : Wiley. - 1616-3028 .- 1616-301X. ; 32:46
-
Journal article (peer-reviewed)abstract
- Potassium–sulfur (K–S) batteries are emerging as low-cost and high-capacity energy-storage technology. However, conventional K–S batteries suffer from two critical issues that have not yet been successfully resolved: the dissolution of potassium polysulfides (KPS) into the liquid electrolyte and the formation of K dendrites on the K metal anode, which lead to inadequate cycling efficiencies with a low reversible capacity. Herein, a high-capacity and long cycle-life K–S battery consisting of a highly concentrated electrolyte (HCE) (4.34 mol kg−1 potassium bis(fluorosulfonyl)imide in a 1,2-Dimethoxyethane) and a sulfurized polyacrylonitrile (SPAN) cathode is presented The application of a HCE efficiently suppresses the dendritic growth of K, as evidenced by operando optical imaging and phase field modeling, owing to the reduced K-ion depletion on the electrode surface and a uniform Faradaic current density over the K metal anode surface. Additionally, because S is covalently bonded to the C backbone of PAN in the SPAN structure, the SPAN cathode inhibits the dissolution of KPS. These features generate synergy that the proposed K–S battery can provide a practical areal capacity of 2.5 mAh cm−2 and unprecedented lifetimes with high Coulombic efficiencies over 700 cycles.
|
|
| 6. |
- Maibach, Julia, 1984, et al.
(author)
-
Toward Operando Characterization of Interphases in Batteries
- 2023
-
In: ACS Materials Letters. - 2639-4979. ; 5:9, s. 2431-2444
-
Research review (peer-reviewed)abstract
- Electrode/electrolyte interfaces are the most importantand leastunderstood components of Li-ion and next-generation batteries. Animproved understanding of interphases in batteries will undoubtedlylead to breakthroughs in the field. Traditionally, evaluating thoseinterphases involves using ex situ surface sensitiveand/or imaging techniques. Due to their very dynamic and reactivenature, ex situ sample manipulation is undesirable.From this point of view, operando surface sensitivetechniques represent a major opportunity to push boundaries in batterydevelopment. While numerous bulk spectroscopic, scattering, and imagingtechniques are well established and widely used, surface sensitive operando techniques remain challenging and, to a largerextent, restricted to the model systems. Here, we give a perspectiveon techniques with the potential to characterize solid/liquid interfacesin both model and realistic battery configurations. The focus is ontechniques that provide chemical and structural information at lengthand time scales relevant for the solid electrolyte interphase (SEI)formation and evolution, while also probing representative electrodeareas. We highlight the following techniques: vibrational spectroscopy,X-ray photoelectron spectroscopy (XPS), neutron and X-ray reflectometry,and grazing incidence scattering techniques. Comprehensive overviews,as well as promises and challenges, of these techniques when used operando on battery interphases are discussed in detail.
|
|
| 7. |
- Masese, Titus, et al.
(author)
-
Honeycomb-Layered Oxides With Silver Atom Bilayers and Emergence of Non-Abelian SU(2) Interactions
- 2023
-
In: Advanced Science. - : Wiley. - 2198-3844 .- 2198-3844. ; 10:6
-
Journal article (peer-reviewed)abstract
- Honeycomb-layered oxides with monovalent or divalent, monolayered cationic lattices generally exhibit myriad crystalline features encompassing rich electrochemistry, geometries, and disorders, which particularly places them as attractive material candidates for next-generation energy storage applications. Herein, global honeycomb-layered oxide compositions, Ag2M2TeO6 ((Formula presented.).) exhibiting (Formula presented.) atom bilayers with sub-valent states within Ag-rich crystalline domains of Ag6M2TeO6 and (Formula presented.) -deficient domains of (Formula presented.) ((Formula presented.)). The (Formula presented.) -rich material characterized by aberration-corrected transmission electron microscopy reveals local atomic structural disorders characterized by aperiodic stacking and incoherency in the bilayer arrangement of (Formula presented.) atoms. Meanwhile, the global material not only displays high ionic conductivity but also manifests oxygen-hole electrochemistry during silver-ion extraction. Within the (Formula presented.) -rich domains, the bilayered structure, argentophilic interactions therein and the expected (Formula presented.) sub-valent states ((Formula presented.), etc.) are theoretically understood via spontaneous symmetry breaking of SU(2)× U(1) gauge symmetry interactions amongst 3 degenerate mass-less chiral fermion states, justified by electron occupancy of silver (Formula presented.) and 5s orbitals on a bifurcated honeycomb lattice. This implies that bilayered frameworks have research applications that go beyond the confines of energy storage.
|
|
| 8. |
- Masese, Titus, et al.
(author)
-
Mixed alkali-ion transport and storage in atomic-disordered honeycomb layered NaKNi 2 TeO 6
- 2021
-
In: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723 .- 2041-1723. ; 12:1
-
Journal article (peer-reviewed)abstract
- Honeycomb layered oxides constitute an emerging class of materials that show interesting physicochemical and electrochemical properties. However, the development of these materials is still limited. Here, we report the combined use of alkali atoms (Na and K) to produce a mixed-alkali honeycomb layered oxide material, namely, NaKNi2TeO6. Via transmission electron microscopy measurements, we reveal the local atomic structural disorders characterised by aperiodic stacking and incoherency in the alternating arrangement of Na and K atoms. We also investigate the possibility of mixed electrochemical transport and storage of Na+ and K+ ions in NaKNi2TeO6. In particular, we report an average discharge cell voltage of about 4 V and a specific capacity of around 80 mAh g–1 at low specific currents (i.e., < 10 mA g–1) when a NaKNi2TeO6-based positive electrode is combined with a room-temperature NaK liquid alloy negative electrode using an ionic liquid-based electrolyte solution. These results represent a step towards the use of tailored cathode active materials for “dendrite-free” electrochemical energy storage systems exploiting room-temperature liquid alkali metal alloy materials.
|
|
| 9. |
- Masese, Titus, et al.
(author)
-
Unveiling structural disorders in honeycomb layered oxide: Na2Ni2TeO6
- 2021
-
In: Materialia. - : Elsevier BV. - 2589-1529. ; 15
-
Journal article (peer-reviewed)abstract
- Honeycomb layered oxides have garnered tremendous research interest in a wide swath of disciplines owing not only to the myriad physicochemical properties they exhibit, but also their rich crystal structural versatility. Herein, a comprehensive crystallographic study of a sodium-based Na2Ni2TeO6 honeycomb layered oxide has been performed using atomic-resolution transmission electron microscopy, elucidating a plethora of atomic arrangement (stacking) disorders in the pristine material. Stacking disorders in the arrangement of honeycomb metal slab layers (stacking faults) occur predominantly perpendicular to the slabs with long-range coherence length and enlisting edge dislocations in some domains. Moreover, the periodic arrangement of the distribution of alkali atoms is altered by the occurrence of stacking faults. The multitude of disorders innate in Na2Ni2TeO6 envisage broad implications in the functionalities of related honeycomb layered oxide materials and hold promise in bolstering renewed interest in their material science. Correction published, see: https://doi.org/10.1016/j.mtla.2021.101104
|
|
| 10. |
- Palluzzi, Matteo, et al.
(author)
-
Ionic Liquids as Cathode Additives for High Voltage Lithium Batteries
- 2024
-
In: Batteries and Supercaps. - 2566-6223. ; In Press
-
Journal article (peer-reviewed)abstract
- Two oxalatoborate ionic liquids (ILs), which are commonly utilized as electrolyte additives that form a protective layer on the cathode surface, are investigated for the first time as electrode additives. Cathodes based on LiNi0.5Mn1.5O4 (LNMO) containing 3 wt % ILs, i. e., “IL-enriched cathodes”, exhibit capacity values above 120 mAh/g with high Coulombic efficiencies throughout cycling over 200 times. A cathode without ILs also exhibits a capacity of 119 mAh/g but its Coulombic efficiency becomes low and unstable after 109 cycles. In addition, when 0.3 M ILs are added to conventional carbonate-based electrolytes, the battery cycle life improves but there is a reduction in the capacity probably due to low ionic conductivity of the electrolyte mixtures. Post-mortem analyses of electrodes retrieved from cycled cells highlight less electrolyte decomposition and less cathode corrosion, enabled by using the IL as the additive in LNMO, which are confirmed by a particle shape with smooth surface identical to the fresh cathode. The study demonstrates that oxalatoborate ILs can be used as the electrode additive, and this provides a new concept for cathode formulations for high performance batteries with a small amount of ILs.
|
|
| 11. |
- Rizell, Josef, 1996
(author)
-
Alkali Metal Stripping and Plating in Liquid Electrolytes
- 2022
-
Licentiate thesis (other academic/artistic)abstract
- Batteries have relatively modest energy densities compared to fossil fuels. In the efforts to make battery-driven transport solutions and technologies competitive with gasoline-powered alternatives, it is important to develop batteries with higher energy densities. This can be enabled by utilizing different electrode materials than what is currently done. For instance, lithium metal is one of the electrode materials which can enable the highest theoretical energy densities. Similarly, using metal anodes can pave way for more sustainable materials solutions based on e.g. sodium, potassium or magnesium. During charging in batteries with a metal anode, ions from the electrolyte are plated on the electrode, and during discharge, the metal is stripped from the electrode. These processes are associated with several problems hindering the practical application of metal anodes. For instance, dendritic or uneven growth can cause short circuits and lead to loss of active material. Further, side reactions can consume both electrolyte and active material. A fundamental understanding of the stripping and plating process is needed to solve these problems. In this thesis, electrochemical measurements are used to understand the fundamental steps of the alkali metal plating and stripping process using Li and K metal electrodes. Additionally, the impact of the electrolyte composition, particularly the salt concentration, on alkali metal anodes is investigated. Cycling performance is evaluated and interphase formation is probed with in situ neutron reflectometry.
|
|
| 12. |
- Rizell, Josef, 1996, et al.
(author)
-
Electrochemical Signatures of Potassium Plating and Stripping
- 2024
-
In: Journal of the Electrochemical Society. - 1945-7111 .- 0013-4651. ; 171:2
-
Journal article (peer-reviewed)abstract
- Alkali metal anodes can enable unmatched energy densities in next generation batteries but suffer from insufficient coulombic efficiencies. To deduce details about processes taking place during galvanostatic cycling, voltage profiles are commonly analyzed, however the interpretation is not straightforward as multiple processes can occur simultaneously. Here we provide a route to disentangle and interpret features of the voltage profile in order to build a mechanistic understanding on alkali metal stripping and deposition, by investigating potassium metal deposition as a model case where processes and reactions are exaggerated due to the high reactivity of potassium. In particular, the importance of separating SEI formation and nucleation to correctly estimate the energy barrier for nucleation is demonstrated. Further, we show how the native layer formed on alkali metal foils gives rise to strong features in the voltage profile and propose forming alkali metal electrode through electrodeposition to mitigate these effects.
|
|
| 13. |
- Rizell, Josef, 1996, et al.
(author)
-
Neutron Reflectometry Study of Solid Electrolyte Interphase Formation in Highly Concentrated Electrolytes
- 2023
-
In: Small Structures. - : WILEY. - 2688-4062. ; 4:11
-
Journal article (peer-reviewed)abstract
- Highly concentrated electrolytes have been found to improve the cycle life and Coulombic efficiency of lithium metal anodes, as well as to suppress dendrite growth. However, the mechanism for these improvements is not well understood. Partly, this can be linked to the difficulty of accurately characterizing the solid electrolyte interphase (SEI), known to play an important role for anode stability and stripping/plating efficiency. Herein, in situ neutron reflectometry is used to obtain information about SEI formation in a highly concentrated ether-based electrolyte. With neutron reflectometry, the thickness, scattering length density (SLD), and roughness of the SEI layer formed on a Cu working electrode are nondestructively probed. The reflectivity data point to the formation of a thin (5 nm) SEI in the highly concentrated electrolyte (salt:solvent ratio 1:2.2), while a considerably thicker (13 nm) SEI is formed in an electrolyte at lower salt concentration (salt:solvent ratio 1:13.7). Further, the SEI formed in the electrolyte with high salt concentration has a higher SLD, suggesting that the chemical composition of the SEI changes. The results from neutron reflectometry correlate well with the electrochemical data from SEI formation.
|
|
