Nanoscale metal fluorides are promising candidates for high capacity lithium ion batteries, in which a conversion reaction upon exposure to Li ions enables access to the multiple valence states of the metal cation. However, little is known about the molecular mechanisms and the reaction pathways in conversion that relate to the need for nanoscale starting materials. To address this reaction and...

Scanning electrochemical microscopy (SECM) inside a glove box was used for the in situ visualization of solid electrolyte interphase (SEI) formation as well as Li-ion intercalation and de-intercalation on anatase TiO2 based paste electrodes.

The ability to intercalate guest species into the van der Waals gap of 2D layered materials affords the opportunity to engineer the electronic structures for a variety of applications. Here we demonstrate the continuous tuning of layer vertically aligned MoS2 nanofilms through electrochemical intercalation of Li(+) ions. By scanning the Li intercalation potential from high to low, we have gaine...

The key factors governing the single-phase or multi-phase structural change behaviors during the intercalation/deintercalation of guest ions have not been well studied and understood yet. Through systematic studies of orthorhombic Fe2(MoO4)3 electrode, two distinct guest ion occupation paths, namely discrete one for Li and pseudo-continuous one for Na, as well as their relationship with single-...

As an alternative to pure lithium-ion, Li+, systems, a hybrid magnesium, Mg2+, and Li+ battery can potentially combine the high capacity, high voltage, and fast Li+ intercalation of Li-ion battery cathodes and the high capacity, low cost, and dendrite-free Mg metal anodes. Herein, we report on the use of two-dimensional titanium carbide, Ti3C2Tx (MXene), as a cathode in hybrid Mg2+/Li+ batterie...

A two-dimensional crystal of molybdenum disulfide (MoS2) monolayer is a photoluminescent direct gap semiconductor in striking contrast to its bulk counterpart. Exfoliation of bulk MoS2 via Li intercalation is an attractive route to large-scale synthesis of monolayer crystals. However, this method results in loss of pristine semiconducting properties of MoS2 due to structural changes that occur ...

Electrochemical impedance spectroscopy (EIS) and in-situ intrinsic resistance measurements were applied to sandwiched disk graphite electrodes to investigate the mechanism of formation of irreversible capacity during initial galvanostatic or potentiostatic lithium intercalation into graphite in four different electrolyte formulations. The stability of the solid electrolyte interphase (SEI) film...

We present an exhaustive first-principles investigation of Li absorption and intercalation in single layer graphene and few layer graphene, as compared to bulk graphite. For single layer graphene, the cluster expansion method is used to systemically search for the lowest energy ionic configuration as a function of absorbed Li content. It is predicted that there exists no Li arrangement that sta...

We have found ultrafast Li(+) intercalation into graphite in a superconcentrated ether electrolyte, even exceeding that in a currently used commercial electrolyte. This discovery is an important breakthrough toward fast-charging Li-ion batteries far beyond present technologies.