Trimethylsiloxy based metal complexes as electrolyte additives for high voltage application in lithium ion cells

Imholt, Laura; Röser, Stephan; Börner, Markus; Streipert, Benjamin; Rad, Babak Rezaei; Winter, Martin; Cekic‐Laskovic, Isidora

doi:10.1016/j.electacta.2017.03.092

Cited by 24 publications

(10 citation statements)

References 38 publications

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“…Fluorinated organic molecules are the largest and most investigated group of functional additives and can be divided further depending on the utilized heteroatoms. [ 66,89–113 ] The two other groups of potential additives for high‐voltage applications are organic metal‐based [ 67,90 ] and lithium salt‐based [ 114–121 ] molecules. All these additives decompose prior to the SOTA electrolyte and form an effective CEI.…”

Section: Effect Of Electrolyte Additive Promoted Cei Formationmentioning

confidence: 99%

Face to Face at the Cathode Electrolyte Interphase: From Interface Features to Interphase Formation and Dynamics

Kuhn

Edström

Winter

et al. 2022

Adv Materials Inter

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Development of high‐performing lithium‐based batteries inevitably calls for a profound understanding and elucidation of the reactivity at the electrode–liquid electrolyte interface and its impact on the overall performance and safety. The formation, composition, properties, and mechanisms of the cathode electrolyte interphase (CEI) formation and function are still to a large extent unknown for most lithium‐based battery materials, whereas the same is well considered for the solid electrolyte interphase on negative electrodes in the literature. In particular, in high voltage regions >4.3 V, the oxidative stability limit of most liquid electrolytes is reached and new mechanisms, involving surface reactivity of the active material beside electrolyte decomposition, contribute to the interfacial reactivity and nature of the CEI. Focusing on lithium‐based cell chemistries, this review aims to highlight the impact of the still less understood electrolyte decomposition chemistry, dictated by the nature of its components, as well as the in‐depth research on the physicochemical and electrochemical properties of CEI formation and evolution at positive electrode material surface and sub‐surfaces.

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Section: Effect Of Electrolyte Additive Promoted Cei Formationmentioning

confidence: 99%

Face to Face at the Cathode Electrolyte Interphase: From Interface Features to Interphase Formation and Dynamics

Kuhn

Edström

Winter

et al. 2022

Adv Materials Inter

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“…In general, it is well-known that commercial NCM-based LIB cells can deliver a cycle life of several hundreds or even thousands of cycles when operated at a cell voltage � 4.3 V. [2,6] However, the high-voltage operation of NCM-based LIB cells is a severe challenge and results in fast and significant capacity fading (e. g., in less than 200 cycles using non-optimized materials/ components), which is sometimes also referred to as "rollover" failure, [21] and has been observed by various researchers. [22][23][24][25][26][27] Even though there are approaches to improve the cycling stability (e. g., by cathode electrolyte interphase (CEI) forming electrolyte additives, cathode surface coatings, etc. ), [21,23,24,28,29] the origin of this failure mechanism and the impact of different cell parameters is not clearly understood so far.…”

Section: Introductionmentioning

confidence: 99%

Exploiting the Degradation Mechanism of NCM523Graphite Lithium‐Ion Full Cells Operated at High Voltage

et al. 2020

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Layered oxides, particularly including Li[NixCoyMnz]O2 (NCMxyz) materials, such as NCM523, are the most promising cathode materials for high‐energy lithium‐ion batteries (LIBs). One major strategy to increase the energy density of LIBs is to expand the cell voltage (>4.3 V). However, high‐voltage NCM∥ graphite full cells typically suffer from drastic capacity fading, often referred to as “rollover” failure. In this study, the underlying degradation mechanisms responsible for failure of NCM523∥ graphite full cells operated at 4.5 V are unraveled by a comprehensive study including the variation of different electrode and cell parameters. It is found that the “rollover” failure after around 50 cycles can be attributed to severe solid electrolyte interphase growth, owing to formation of thick deposits at the graphite anode surface through deposition of transition metals migrating from the cathode to the anode. These deposits induce the formation of Li metal dendrites, which, in the worst cases, result in a “rollover” failure owing to the generation of (micro‐) short circuits. Finally, approaches to overcome this dramatic failure mechanism are presented, for example, by use of single‐crystal NCM523 materials, showing no “rollover” failure even after 200 cycles. The suppression of cross‐talk phenomena in high‐voltage LIB cells is of utmost importance for achieving high cycling stability.

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“…Substantial increases in the amount of TEAB could possibly cause a deterioration of the physicochemical properties of the electrolyte, such as its viscosity and ionic conductivity, thereby hindering Li + migration. 43,44 Moreover, 0.1% and 0.5% TEAB could form an effective CEI layer on the surface of NCM811 cathode materials, thereby preventing the occurrence of undesired reactions on the NCM811 cathode materials. This implies that the use of TEAB in cells at amounts up to 1.0% would provide acceptable performance, as TEAB at that concentration does not appear to compromise the kinetic behavior of Li + migration.…”

Section: Resultsmentioning

confidence: 99%

“…By contrast, the cells cycled with 2.0% TEAB showed relatively strong polarization, which might indicate a reducing in the ionic conductivity with increasing amounts of TEAB (standard electrolyte: 9.11 mS cm −1 , 0.05% TEAB: 9.06 mS cm −1 , 0.1% TEAB: 9.00 mS cm −1 , 0.5% TEAB: 8.85 mS cm −1 , 1.0% TEAB: 8.47 mS cm −1 , and 2.0% TEAB: 8.25 mS cm −1 ). Substantial increases in the amount of TEAB could possibly cause a deterioration of the physicochemical properties of the electrolyte, such as its viscosity and ionic conductivity, thereby hindering Li + migration 43,44 . Moreover, 0.1% and 0.5% TEAB could form an effective CEI layer on the surface of NCM811 cathode materials, thereby preventing the occurrence of undesired reactions on the NCM811 cathode materials.…”

Section: Resultsmentioning

confidence: 99%

Triethanolamine borate as a surface stabilizing bifunctional additive for Ni‐rich layered oxide cathode

et al. 2020

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Summary Ni‐rich cathode materials have been receiving substantial highlight because of its large specific capacity, however, they suffer from inferior cycling results owing to occurring undesired reactions in the cell. Herein, triethanolamine borate (TEAB), containing borate and ethanolamine groups, is proposed as a functional additive because it spontaneously suppresses electrolyte decomposition while inhibiting Ni dissolution in Ni‐rich cathodes. The electrochemical oxidation of TEAB first generates borate‐based cathode‐electrolyte interphases for the Ni‐rich cathode, which effectively suppress the electrolyte decomposition. A cell controlled with TEAB showed a greatly decreased internal pressure, which improved the safety performance of the cell. Notably, even the inclusion of 0.1% TEAB in the cell markedly increased the cycling performance from 32.0% to 63.2%. Cells cycled with TEAB showed stable retention rate after 100 cycles at high temperature. Results of high‐temperature storage of the cells confirmed improvements as changes in the open‐circuit potentials, thickness of the cell, and the recovery rate for specific capacity. TEAB is also efficient for suppressing Ni dissolution because TEAB selectively scavenges fluoride species by a chemical scavenging reaction. The cell evaluated with TEAB‐containing electrolyte exhibited a releasing 140.3 ppm of dissolved Ni, whereas the cell evaluated with bare electrolyte released 643.6 ppm.

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Trimethylsiloxy based metal complexes as electrolyte additives for high voltage application in lithium ion cells

Cited by 24 publications

References 38 publications

Face to Face at the Cathode Electrolyte Interphase: From Interface Features to Interphase Formation and Dynamics

Face to Face at the Cathode Electrolyte Interphase: From Interface Features to Interphase Formation and Dynamics

Exploiting the Degradation Mechanism of NCM523Graphite Lithium‐Ion Full Cells Operated at High Voltage

Triethanolamine borate as a surface stabilizing bifunctional additive for Ni‐rich layered oxide cathode

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