In Situ Growing Chromium Oxynitride Nanoparticles on Carbon Nanofibers to Stabilize Lithium Deposition for Lithium Metal Anodes

To address the dendrite growth and interface instability of high-capacity Li metal anode, heterogeneous seed-decorated 3D host materials are expected to suppress the growth of Li dendrites. The physical stability and chemical reactivity of these nanoseeds are the decisive conditions for long cycling lithium metal batteries. Herein, carbon nanofibers decorated with uniform CrO0.78N0.48 nanoparticles (ACrCFs) are synthesized by a novel in situ growing method, where the size, composition, distribution, and migration behavior of these nanoparticles are controlled by the introduction of asphaltene. As the 3D host materials for Li anodes, ACrCFs exhibit an excellent lithiophilicity, a superior mixed ion-electron conductivity, and abundant electrochemical active sites. Thus, the ACrCF-modified Li anodes deliver a smooth Li morphology, low nucleation overpotential (10.4 mV), superior cyclic stability with 320 stable cycles (Coulombic efficiency, >98.0%) at 1 mA cm-2, and excellent plating/stripping stability over 1000 h. Notably, no obvious detachment or chalking of these nanoparticles occur during the cycling process. The full cell with LiFePO4 cathode also delivers a better rate capability with more stable cycling performance. The homogeneous CrO0.78N0.48 nanoparticles achieved by this in situ growing method also promise a facile method for the potential applications of transition-metal oxynitride for high energy density battery systems.

Atomic layer deposited tungsten nitride thin films as a new lithium-ion battery anode

Atomic layer deposited WN_x thin films are used as a new Li-ion battery anode whose capacity can be enhanced further by depositing the film on a MWCNT scaffold layer.

Atomic layer deposited molybdenum nitride thin film: a promising anode material for Li ion batteries

Molybdenum nitride (MoNx) thin films are deposited by atomic layer deposition (ALD) using molybdenum hexacarbonyl [Mo(CO)6] and ammonia [NH3] at varied temperatures. A relatively narrow ALD temperature window is observed. In situ quartz crystal microbalance (QCM) measurements reveal the self-limiting growth nature of the deposition that is further verified with ex situ spectroscopic ellipsometry and X-ray reflectivity (XRR) measurements. A saturated growth rate of 2 Å/cycle at 170 °C is obtained. The deposition chemistry is studied by the in situ Fourier transform infrared spectroscopy (FTIR) that investigates the surface bound reactions during each half cycle. As deposited films are amorphous as observed from X-ray diffraction (XRD) and transmission electron microscopy electron diffraction (TEM ED) studies, which get converted to hexagonal-MoN upon annealing at 400 °C under NH3 atmosphere. As grown thin films are found to have notable potential as a carbon and binder free anode material in a Li ion battery. Under half-cell configuration, a stable discharge capacity of 700 mAh g(-1) was achieved after 100 charge-discharge cycles, at a current density of 100 μA cm(-2).

X-ray absorption spectroscopy and energy storage of Ni-doped cobalt nitride, (Ni(0.33)Co(0.67))N, prepared by a simple synthesis route

Metal nitride (Ni(0.33)Co(0.67))N nanoparticles are prepared by nitridation using NiCo(2)O(4) as a precursor material by heating at 335 °C for 2 h in flowing NH(3) + N(2) gas and characterized by X-ray diffraction (XRD), field emission-scanning electron microscopy (FE-SEM), high resolution-transmission electron microscopy (HR-TEM), along with selective area electron diffraction (SAED) and X-ray absorption spectroscopy (XAS) techniques. The X-ray absorption near edge structure (XANES) at the Co K-edge showed that the oxidation state of cobalt is close to 3+. The (Ni(0.33)Co(0.67))N showed a shift in edge energy towards lower values due to Ni-doping to cobalt site. The Li-storage behaviour of (Ni(0.33)Co(0.67))N nanoparticles was evaluated by galvanostatic cycling and cyclic voltammetry in the cells with Li-metal as counter electrode in the voltage range of 0.005-3.0 V at ambient temperature. When cycled at 250 mA g(-1), the first-cycle reversible capacity of 700 (±5) mA h g(-1) (~1.9 moles of Li) is obtained. It showed an initial decrease in capacity until the 10(th) cycle and a stable capacity of 400 (±5) mA h g(-1) (~1.09 moles of Li) is observed at the end of the 50(th) cycle. Excellent rate capability is also shown when cycling at 500 mA g(-1) (up to 50 cycles). The materials showed excellent Li-ion insertion/extraction, with the coulombic efficiency reaching almost 99% in the range of 10-50 cycles. The average charge and discharge potentials are ~2.03 and ~1.0 V, respectively for the decomposition/formation of Li(3)N as determined by electroanalytical techniques.