Solving the problems with Li-air batteries come as close possible to theoretical limits for energy density in a battery. By weight, this is roughly 10 times higher than conventional lithium-ion and would be sufficient power cars range comparable those gasoline engines. But engineering battery has been challenge. Liu et al. managed overcome remaining challenges: They were able avoid electrode passivation, turn limited solvent stability into an advantage, eliminate fatal caused by superoxides,...

Li-substituted layered P2–Na0.80[Li0.12Ni0.22Mn0.66]O2 is investigated as an advanced cathode material for Na-ion batteries. Both neutron diffraction and nuclear magnetic resonance (NMR) spectroscopy are used to elucidate the local structure, they reveal that most of Li ions located in transition metal (TM) sites, preferably surrounded by Mn ions. To characterize structural changes occurring upon electrochemical cycling, situ synchrotron X-ray conducted. It clearly demonstrated no...

We have synthesized the products of fluoroethylene carbonate (FEC) and vinylene (VC) via lithium naphthalenide reduction. By analyzing resulting solid precipitates gas evolution, our results confirm that both FEC VC decomposition include HCO2Li, Li2C2O4, Li2CO3, polymerized VC. For FEC, experimental data supports a reduction mechanism where reduces to form LiF, followed by subsequent In product, Li2CO3 were found in smaller quantities than with no additional fluorine environments being...

The solid electrolyte interphase (SEI) of the high capacity anode material Si is monitored over multiple electrochemical cycles by (7)Li, (19)F, and (13)C solid-state nuclear magnetic resonance spectroscopies, with organics dominating SEI. Homonuclear correlation experiments are used to identify organic fragments -OCH2CH2O-, -OCH2CH2-, -OCH2CH3, -CH2CH3 contained in both oligomeric species lithium semicarbonates ROCO2Li, RCO2Li. SEI growth correlated increasing electrode tortuosity using...

Active control over the shape, composition, and crystalline habit of nanocrystals has long been a goal. Various methods have shown to enable postsynthesis modification nanoparticles, including use Kirkendall effect, galvanic replacement, cation or anion exchange, all taking advantage enhanced solid-state diffusion on nanoscale. In these processes, however, alteration nanoparticles requires introduction new precursor materials. Here we show that for cesium lead halide perovskite reversible...

Electrochemical cells, in the form of batteries (or supercapacitors) and fuel are efficient devices for energy storage conversion. These show considerable promise use portable static to power electronics various modes transport produce store electricity both locally on grid. For example, high density lithium-ion being developed hybrid electric vehicles where they improve efficiency help reduce greenhouse gas emissions. To gain insight into chemical reactions involving multiple components...

Conversion materials for lithium ion batteries have recently attracted considerable attention due to their exceptional specific capacities. Some metal fluorides, such as CuF2, are promising candidates cathode owing high operating potential, which stems from the electronegativity of fluorine. However, ionicity metal–fluorine bond leads a large band gap that renders these poor electronic conductors. Nanosizing active material and embedding it within conductive matrix carbon can greatly improve...

The solid electrolyte interphase (SEI) passivating layer that grows on all battery electrodes during cycling is critical to the long-term capacity retention of lithium-ion batteries. Yet, it inherently difficult study because its nanoscale thickness, amorphous composite structure, and air sensitivity. Here, we employ an experimental strategy using 1H, 7Li, 19F, 13C solid-state nuclear magnetic resonance (ssNMR) gain insight into decomposition products in SEI formed silicon electrodes,...

Vanadium sulfide VS4 in the patronite mineral structure is a linear chain compound comprising vanadium atoms coordinated by disulfide anions [S2](2-). (51)V NMR shows that material, despite having V formally d(1) configuration, diamagnetic, suggesting potential dimerization through metal-metal bonding associated with Peierls distortion of chains. This supported density functional calculations, and also consistent observed alternation V-V distances 2.8 3.2 Å along Partial lithiation results...

The high theoretical gravimetric capacity of the Li-S battery system makes it an attractive candidate for numerous energy storage applications. In practice, cell performance is plagued by low practical and poor cycling. effort to explore mechanism discharge with goal better understanding performance, we examine phase diagram using computational techniques complement this in situ (7)Li NMR study during discharge. Both experimental studies are consistent suggestion that only solid product...

Micrometer-sized LiNixMn2–xO4 (0.3 ≤ x 0.5) single crystals with (111) surface facets were synthesized and characterized by 6Li magic angle spinning nuclear magnetic resonance, Fourier transform infrared spectroscopy, electrochemical studies. All three techniques sensitive to cation disorder the corroborated results showed that structural ordering improves x. The transition from ordered disordered spinel was triggered an increase in Mn3+ content, which accomplished either a change chemical...

In recent years magic angle spinning-dynamic nuclear polarization (MAS-DNP) has developed as an excellent approach for boosting the sensitivity of solid-state NMR (ssNMR) spectroscopy, thereby enabling characterization challenging systems in biology and chemistry. Most commonly, MAS-DNP is based on use nitroxide biradicals polarizing agents. materials science, since nitroxides often limits signal enhancement to materials' surface subsurface layers, there need hyperpolarization approaches...

Solid-state nuclear magnetic resonance (NMR) spectroscopy has increasingly been used for materials characterization as it enables selective detection of elements interest, well their local structure and dynamic properties. Nevertheless, utilization NMR is limited by its inherent low sensitivity. The development polarization (DNP) approaches, which provide enormous sensitivity gain in through the transfer from electron spins, transformed application solid-state science. In this review, we...

A multi-nuclear solid-state NMR approach is employed to investigate the lithium-air battery, monitor evolution of electrochemical products formed during cycling, and gain insight into processes affecting capacity fading. While lithium peroxide identified by

A closer look: Solid-state 7Li and 17O NMR spectroscopy is a valuable tool in the characterization of products formed lithium–oxygen battery, necessary step development viable cell. Since lithium peroxide, desired discharge product, has unique signature, it can be clearly identified. Detailed facts importance to specialist readers are published as ”Supporting Information”. Such documents peer-reviewed, but not copy-edited or typeset. They made available submitted by authors. Please note: The...

Forming a stable solid electrolyte interphase (SEI) is critical for rechargeable batteries' performance and lifetime. Understanding its formation requires analytical techniques that provide molecular-level insight. Here, dynamic nuclear polarization (DNP) utilized the first time to enhance sensitivity of solid-state NMR (ssNMR) spectroscopy SEI. The approach demonstrated on reduced graphene oxide (rGO) cycled in Li-ion cells natural abundance 13C-enriched solvents. Our results indicate DNP...

Lithium–sulfur (Li–S) batteries (LSBs) have high energy densities and employ inexpensive materials. However, the poor sulfur conductivity rapid capacity fading hamper their applications. We developed a free-standing composite cathode based on multi-walled carbon nanotubes (MWCNTs) single-walled (SWCNTs), whose fabrication follows solution-based, scalable method. The two CNT types create synergic effect: SWCNTs result in conductivity, surface area, mechanical strength/flexibility; MWCNTs'...

The solvothermal reactions of Ti(OEt)4 with LnCl3 (Ln=La, Ce) produced new Ti28Ln cages, in which the Ln3+ ions are coordinated within a metallocrown arrangement, represents highest nuclearity cages this type (see figure).

In situ synchrotron diffraction measurements and subsequent Rietveld refinements are used to show that the high energy density cathode material LiCoPO4 (space group Pnma) undergoes two distinct two-phase reactions upon charge discharge, both occurring via an intermediate Li2/3(Co2+)2/3(Co3+)1/3PO4 phase. Two resonances observed for Li2/3CoPO4 with intensity ratios of 2:1 1:1 in 31P 7Li NMR spectra, respectively. An ordering Co2+/Co3+ oxidation states is proposed within a (a × 3b c)...

Mobi-Li-ty: Lithium mobility, as a function of temperature during battery cycling, can be simply monitored by using in situ T2' relaxation measurements. Since Li dynamics are strongly related to structural properties, the changes used detect changes, such ordering.

DFT calculations are used to assign and rationalise the local environments in the³¹P NMR spectra of LiFe_xCo_1−xPO₄.