Choosing the best molecular precursor to prepare Li4Ti5O12 by the sol–gel method using 1H NMR: evidence of [Ti3(OEt)13]− in solution

Garcı́a-Herbosa, Gabriel; Aparicio, Mario; Mosa, Jadra; Cuevas, José V.; Torroba, Tomás

doi:10.1039/c6dt01949h

“…By analyzing the electrolyte solutions after cycling in Li∥Li cells, we identified the peak at 3.71 ppm chemical shift to correspond to H in CH 3 ‐ CH 2 ‐O‐Li (Figure 4 b). [43] The experimental evidence supports that Pathway I is more likely, consistent with the understanding inferred from DFT calculations. It is worth noting that we also calculated the NMR chemical shifts of CH 3 CH 2 OLi, and the result was in good agreement of our measured values (Figure S14).…”

Section: Resultssupporting

confidence: 80%

Enabling Lithium Metal Anode in Nonflammable Phosphate Electrolyte with Electrochemically Induced Chemical Reactions

Zhang

¹

,

Luo

²

,

Miao

³

et al. 2021

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Lithium metal anode holds great promises for next‐generation battery technologies but is notoriously difficult to work with. The key to solving this challenge is believed to lie in the ability of forming stable solid‐electrolyte interphase (SEI) layers. To further address potential safety issues, it is critical to achieve this goal in nonflammable electrolytes. Building upon previous successes in forming stable SEI in conventional carbonate‐based electrolytes, here we report that reversible Li stripping/plating could be realized in triethyl phosphate (TEP), a known flame retardant. The critical enabling factor of our approach was the introduction of oxygen, which upon electrochemical reduction induces the initial decomposition of TEP and produces Li3PO4 and poly‐phosphates. Importantly, the reaction was self‐limiting, and the resulting material regulated Li plating by limiting dendrite formation. In effect, we obtained a functional SEI on Li metal in a nonflammable electrolyte. When tested in a symmetric Li∥Li cell, more than 300 cycles of stripping/plating were measured at a current density of 0.5 mA cm−2. Prototypical Li‐O2 and Li‐ion batteries were also fabricated and tested to further support the effectiveness of this strategy. The mechanism by which the SEI forms was studied by density functional theory (DFT), and the predictions were corroborated by the successful detection of the intermediates and products.

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“…By analyzing the electrolyte solutions after cycling in Li k Li cells,w ei dentified the peak at 3.71 ppm chemical shift to correspond to Hi nC H 3 -CH 2 -O-Li (Figure 4b). [43] Thee xperimental evidence supports that Pathway I is more likely,c onsistent with the understanding inferred from DFT calculations.I ti sw orth noting that we also calculated the NMR chemical shifts of CH 3 CH 2 OLi, and the result was in good agreement of our measured values (Figure S14). We next studied the SEI by Fourier-transform infrared spectroscopy (FTIR).…”

Section: Angewandte Chemiesupporting

confidence: 73%

Enabling Lithium Metal Anode in Nonflammable Phosphate Electrolyte with Electrochemically Induced Chemical Reactions

Zhang

¹

,

Luo

²

,

Miao

³

et al. 2021

View full text Add to dashboard Cite

Lithium metal anode holds great promises for next‐generation battery technologies but is notoriously difficult to work with. The key to solving this challenge is believed to lie in the ability of forming stable solid‐electrolyte interphase (SEI) layers. To further address potential safety issues, it is critical to achieve this goal in nonflammable electrolytes. Building upon previous successes in forming stable SEI in conventional carbonate‐based electrolytes, here we report that reversible Li stripping/plating could be realized in triethyl phosphate (TEP), a known flame retardant. The critical enabling factor of our approach was the introduction of oxygen, which upon electrochemical reduction induces the initial decomposition of TEP and produces Li3PO4 and poly‐phosphates. Importantly, the reaction was self‐limiting, and the resulting material regulated Li plating by limiting dendrite formation. In effect, we obtained a functional SEI on Li metal in a nonflammable electrolyte. When tested in a symmetric Li∥Li cell, more than 300 cycles of stripping/plating were measured at a current density of 0.5 mA cm−2. Prototypical Li‐O2 and Li‐ion batteries were also fabricated and tested to further support the effectiveness of this strategy. The mechanism by which the SEI forms was studied by density functional theory (DFT), and the predictions were corroborated by the successful detection of the intermediates and products.

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“…The calculated lattice spacing is in agreement with JCPDS (Joint Committee on Powder Diffraction Standards) reference card no. 49-0207 for the pure spinel phase Li 4 Ti 5 O 12 structure [ 20 , 22 ]. Amorphous areas are detected in the images, which can be attributed to carbon content.…”

Section: Resultsmentioning

confidence: 99%

“…However, lithium titanate, Li 4 Ti 5 O 12 (LTO), is a promising candidate to replace graphite as an anode material in LIBs, avoiding the formation of solid electrolyte interphase (SEI), losses of Li + , and improving LIB performance. Another advantage is the zero-strain during intercalation which imparts LTO with a very long lifespan [ 15 , 16 , 17 , 18 , 19 , 20 , 21 , 22 ]. Nevertheless, LTO has a low theoretical capacity (175 mAh g −1 ) and a low conductivity (10 −8 –10 −13 Scm −1 ) [ 23 ].…”

Section: Introductionmentioning

confidence: 99%

Sol-Gel Synthesis of Nanocrystalline Mesoporous Li4Ti5O12 Thin-Films as Anodes for Li-Ion Microbatteries

Mosa

¹

,

Aparicio

²

2020

Self Cite

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The development of anodes based on Li4Ti5O12 (LTO) for lithium ion batteries has become very important in recent years on the basis that it allows a long service life (stability in charge-discharge cycling) and safety improvements. The processing of this material in the form of thin film allows for greater control of its characteristics and an improvement of its disadvantages, namely reduced electrical conductivity and low diffusion of lithium ions. In this work, we try to limit these disadvantages through the synthesis of a mesostructured carbon-doped Li4Ti5O12 thin-film with a pure spinel phase using a combination of a block-copolymer template and in situ synthesis of Li-Ti double alkoxide. Structural and electrochemical characterization has been carried out to determine the best conditions (temperature, time, atmosphere) for the thermal treatment of the material to reach a compromise between crystallinity and porosity distribution (pore size, pore volume, and interconnectivity).

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Choosing the best molecular precursor to prepare Li₄Ti₅O₁₂ by the sol–gel method using ¹H NMR: evidence of [Ti₃(OEt)₁₃]⁻ in solution

Cited by 5 publications

References 49 publications

Enabling Lithium Metal Anode in Nonflammable Phosphate Electrolyte with Electrochemically Induced Chemical Reactions

Enabling Lithium Metal Anode in Nonflammable Phosphate Electrolyte with Electrochemically Induced Chemical Reactions

Enabling Lithium Metal Anode in Nonflammable Phosphate Electrolyte with Electrochemically Induced Chemical Reactions

Sol-Gel Synthesis of Nanocrystalline Mesoporous Li4Ti5O12 Thin-Films as Anodes for Li-Ion Microbatteries

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