Abundant grain boundaries activate highly efficient lithium ion transportation in high rate Li4Ti5O12 compact microspheres

Xiao

et al. 2021

Processes

Li4Ti5O12 (LTO), known as a zero-strain material, is widely studied as the anode material for lithium-ion batteries owing to its high safety and long cycling stability. However, its low electronic conductivity and Li diffusion coefficient significantly deteriorate its high-rate performance. In this work, we proposed a facile approach to introduce oxygen vacancies into the commercialized LTO via thermal treatment under Ar/H2 (5%). The oxygen vacancy-containing LTO demonstrates much better performance than the sample before H2 treatment, especially at high current rates. Density functional theory calculation results suggest that increasing oxygen vacancy concentration could enhance the electronic conductivity and lower the diffusion barrier of Li+, giving rise to a fast electrochemical kinetic process and thus improved high-rate performance.

Section: Resultsmentioning

confidence: 99%

Introducing Oxygen Vacancies in Li4Ti5O12 via Hydrogen Reduction for High-Power Lithium-Ion Batteries

Xiao

et al. 2021

Processes

“…In addition, Ma et al. prepared compact anode materials (Li 4 Ti 5 O 12 , LTO) in the form of microspheres which contain closely packed nanoparticles . Scanning transmission electron microscopy (STEM) combined with electron energy loss spectroscopy (EELS) was used to identify spatial distribution of lithium ions in the densely packed LTO nanograins.…”

Section: Theory Of Lithium Ion Transport In Solid‐state Electrodesmentioning

confidence: 99%

“…Scanning transmission electron microscopy (STEM) combined with electron energy loss spectroscopy (EELS) was used to identify spatial distribution of lithium ions in the densely packed LTO nanograins. As the LTO‐based cells were discharged to 60 % state of charge (SOC), an anisotropic distribution of lithium ions gathering along grain boundaries was observed (Figure a and b), which implies that grain boundaries can provide fast ionic diffusion pathways because of the present point defects (vacancies) that facilitate the intercalation of ions into the lattice next to the boundaries. As a result, the grain boundaries can establish an efficient ionic migration network throughout LTO microspheres, as proposed in Figure c…”

Section: Theory Of Lithium Ion Transport In Solid‐state Electrodesmentioning

confidence: 99%

“… (a) STEM and (b) EELS images of LTO microspheres at 60 % SOC ((b) shows enlarged details of lithium ion distribution in the rectangle in (a)); (c) lithiation mechanism along the boundary of nanograins (intercalation of lithium ions initiates at the grain boundaries and lithium ions then tend to intercalate into lattice next to grain boundaries as the lithiation reaction processes) . Reproduced with permission from Ref.…”

Section: Theory Of Lithium Ion Transport In Solid‐state Electrodesmentioning

confidence: 99%

See 1 more Smart Citation

Recent Developments of Nanomaterials and Nanostructures for High‐Rate Lithium Ion Batteries

et al. 2020

ChemSusChem

techniques, based on either electrochemical or radiology methodologies, are covered as well. In addition, state-of-the-art research findings are provided to illustrate the effect of nanomaterials and nanostructures in promoting the rate performance of lithium ion batteries. Finally, several challenges and shortcomings of applying nanotechnology in fabricating highrate lithium ion batteries are summarised.

“…Spinel lithium titanite (Li 4 Ti 5 O 12 , LTO), as a high‐rate anodic electrode of LIBs, has roused much attention . Unlike many other anodes (such as graphite, silicon, and lithium metal) with large volume expansion during Li‐ion insertion/deinsertion process, LTO with its “zero‐strain” characteristics can maintain excellent structural stability and good redox reactivity at high rates . However, its high‐rate application is limited by the low electronic and ionic conductivity in bulk LTO.…”

Section: Introductionmentioning

confidence: 99%

Ti³⁺ Self‐Doped Li₄Ti₅O₁₂ Anchored on N‐Doped Carbon Nanofiber Arrays for Ultrafast Lithium‐Ion Storage

Yao

Yin

et al. 2019

Small

The ORCID identification number(s) for the author(s) of this article can be found under https://doi.org/10.1002/smll.201905296. Omnibearing acceleration of charge/ion transfer in Li 4 Ti 5 O 12 (LTO) electrodes is of great significance to achieve advanced high-rate anodes in lithium-ion batteries. Here, a synergistic combination of hydrogenated LTO nanoparticles (H-LTO) and N-doped carbon fibers (NCFs) prepared by an electrodepositionatomic layer deposition method is reported. Binder-free conductive NCFs skeletons are used as strong support for H-LTO, in which Ti 3+ is self-doped along with oxygen vacancies in LTO lattice to realize enhanced intrinsic conductivity. Positive advantages including large surface area, boosted conductivity, and structural stability are obtained in the designed H-LTO@NCF electrode, which is demonstrated with preeminent high-rate capability (128 mAh g −1 at 50 C) and long cycling life up to 10 000 cycles. The full battery assembled by H-LTO@NCFs anode and LiFePO 4 cathode also exhibits outstanding electrochemical performance revealing an encouraging application prospect. This work further demonstrates the effectiveness of self-doping of metal ions on reinforcing the high-rate charge/discharge capability of batteries. www.advancedsciencenews.com