Phase Transformation of Doped LiCoPO during Galvanostatic Cycling.

In situ X-ray diffraction was employed to investigate the crystal structure changes in Cr/Si co-doped Li(Co,Fe)PO cathode material during a galvanostatic charge/discharge process at a slow rate of C/30. The evolution of the X-ray patterns revealed that the phase transformation between the Cr/Si-Li(Co,Fe)PO and Cr/Si-(Co,Fe)PO is a two-step process, which involves the formation of an intermediate compound of Cr/Si-Li(Co,Fe)PO upon the extraction of Li ions from the pristine phase. Different from the previously reported two biphasic transition steps, the phase transformation of the Cr/Si-Li(Co,Fe)PO followed a solid solution and a biphasic reaction pathway at different stages of the delithiation/lithiation process, respectively.

Boosting Ultra-Fast Charge Battery Performance: Filling Porous nanoLiTiO Particles with 3D Network of N-doped Carbons.

Lithium titanium oxide (LiTiO)-based cells are a promising technology for ultra-fast charge-discharge and long life-cycle batteries. However, the surface reactivity of LiTiO and lack of electronic conductivity still remains problematic. One of the approaches toward mitigating these problems is the use of carbon-coated particles.

High Capacity and High Efficiency Maple Tree-Biomass-Derived Hard Carbon as an Anode Material for Sodium-Ion Batteries.

Sodium-ion batteries (SIBs) are in the spotlight because of their potential use in large-scale energy storage devices due to the abundance and low cost of sodium-based materials. There are many SIB cathode materials under investigation but only a few candidate materials such as carbon, oxides and alloys were proposed as anodes. Among these anode materials, hard carbon shows promising performances with low operating potential and relatively high specific capacity.

High-Capacity and Long-Cycle Life Aqueous Rechargeable Lithium-Ion Battery with the FePO Anode.

Aqueous lithium-ion batteries are emerging as strong candidates for a great variety of energy storage applications because of their low cost, high-rate capability, and high safety. Exciting progress has been made in the search for anode materials with high capacity, low toxicity, and high conductivity; yet, most of the anode materials, because of their low equilibrium voltages, facilitate hydrogen evolution. Here, we show the application of olivine FePO and amorphous FePO·2HO as anode materials for aqueous lithium-ion batteries.

Measuring Spatially Resolved Collective Ionic Transport on Lithium Battery Cathodes Using Atomic Force Microscopy.

One of the main challenges in improving fast charging lithium-ion batteries is the development of suitable active materials for cathodes and anodes. Many materials suffer from unacceptable structural changes under high currents and/or low intrinsic conductivities. Experimental measurements are required to optimize these properties, but few techniques are able to spatially resolve ionic transport properties at small length scales.

Hollow melon-seed-shaped lithium iron phosphate micro- and sub-micrometer plates for lithium-ion batteries.

Melon-seed-shaped LiFePO4 hollow micro- and sub-micrometer plates have been synthesized via a polyol-assisted hydrothermal method. The as-prepared LiFePO4 hollow materials were new with regard to their single-crystalline shells with large ac surfaces. Based on the detailed analysis of time-dependent studies, a possible growth mechanism was proposed involving nucleation, anisotropic growth, selective etching, and reversed recrystallization.