Rechargeable aqueous metal-ion batteries made from non-flammable and low-cost materials offer promising opportunities in large-scale utility grid applications, yet low voltage and energy output, as well as limited cycle life remain critical drawbacks in their electrochemical operation. Here we develop a series of high-voltage aqueous metal-ion batteries based on 'M(+)/N(+)-dual shuttles' to ove...

Despite their ubiquitous usage and increasing societal dependence on Li-ion batteries, there remains a lack of detailed empirical evidence Li intercalation/deintercalation into graphite even though this process dictates the performance, longevity, safety system. Here, we report direct detection dissociation specific crystallographic phases in lithiated graphite, which form through stepwise stag...

Control over the doping density in copper sulfide nanocrystals is of great importance and determines its use in optoelectronic applications such as NIR optical switches and photovoltaic devices. Here, we demonstrate that we can reversibly control the hole carrier density (varying from >1022 cm-3 to intrinsic) in copper sulfide nanocrystals by electrochemical methods. We can control the type of ...

Graphite is the dominant anode material for lithium-ion batteries; however, it still suffers from Li-plating when charging fast or at low temperature, and associated with performance fading safety concerns. Herein, we clarify mechanism of lithium evolution graphite particles by over-lithiation cycle test, in-situ XRD, titration gas chromatography. We observe that intercalation compounds (GICs, ...

The rapid insertion and extraction of Li ions from a cathode material is imperative for the functioning of a Li-ion battery. In many cathode materials such as LiCoO2, lithiation proceeds through solid-solution formation, whereas in other materials such as LiFePO4 lithiation/delithiation is accompanied by a phase transition between Li-rich and Li-poor phases. We demonstrate using scanning transm...

Intercalation provides to the host materials a means for controlled variation of many physical/chemical properties and dominates reactions in metal-ion batteries. Of particular interest is graphite intercalation compounds with intriguing staging structures, which however are still unclear, especially their nanostructure dynamic transition mechanism. Herein, nature structure evolution lithium (L...

First-principles calculations based on density functional theory are carried out to investigate the Li storage capability of graphitic carbon nitride nanotubes. The porous nanotubes provide unprecedented opportunity for energy storage due to their uniform size of pores in the wall and doubly bonded nitrogen at the edges of the pore. The calculations predict that the Li atoms can easily access t...

We studied the influence of defect density in multilayer graphene sheets on intercalation Li ions by means x-ray photoelectron spectroscopy. The was prepared chemical vapor deposition Ni substrates. at room temperature results immediate intercalation, while additional annealing 300 °C partially removes from sample surface. found that varying over several orders magnitude does not process. propo...

Pseudocapacitance is commonly associated with surface or near-surface reversible redox reactions, as observed with RuO2·xH2O in an acidic electrolyte. However, we recently demonstrated that a pseudocapacitive mechanism occurs when lithium ions are inserted into mesoporous and nanocrystal films of orthorhombic Nb2O5 (T-Nb2O5; refs 1,2). Here, we quantify the kinetics of charge storage in T-Nb2O5...