Li-ion battery materials: present and future

Metal Oxides and Oxysalts as Anode Materials for Li Ion Batteries

Graphene/metal oxide composite electrode materials for energy storage

Electrochemical capacitors, so-called supercapacitors, play an important role in energy storage and conversion systems. In the last decade, with the increasing volume of scientific activity and publications in this field, researchers have developed better tools to improve electrode materials. Although carbonaceous materials seem the most suitable for supercapacitor applications, a large diversity of materials has been proposed and studied. Yet, in order to accomplish performance beyond the limitations of each material, mainly in terms of energy density and durability, composite materials have been implemented, most of them being the combinations of carbon-based materials and other components. In this review, we present the recent advances in the field of composite materials that include at least one carbon-based component for supercapacitor electrodes. We focus on cases in which a single material by itself suffers from a drawback that can be overcome by combining it with other components, enabling the fabrication of a composite material with enhanced performance. We present several important compositions as well as the major routes of synthesis, characterization and performance of composite materials in this field.

Carbon-based composite materials for supercapacitor electrodes: a review

We created unique interconnected partially graphitic carbon nanosheets (10–30 nm in thickness) with high specific surface area (up to 2287 m2 g–1), significant volume fraction of mesoporosity (up to 58%), and good electrical conductivity (211–226 S m–1) from hemp bast fiber. The nanosheets are ideally suited for low (down to 0 °C) through high (100 °C) temperature ionic-liquid-based supercapacitor applications: At 0 °C and a current density of 10 A g–1, the electrode maintains a remarkable capacitance of 106 F g–1. At 20, 60, and 100 °C and an extreme current density of 100 A g–1, there is excellent capacitance retention (72–92%) with the specific capacitances being 113, 144, and 142 F g–1, respectively. These characteristics favorably place the materials on a Ragone chart providing among the best power–energy characteristics (on an active mass normalized basis) ever reported for an electrochemical capacitor: At a very high power density of 20 kW kg–1 and 20, 60, and 100 °C, the energy densities are 19, 3...

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Interconnected Carbon Nanosheets Derived from Hemp for Ultrafast Supercapacitors with High Energy

Effect of solid electrolyte interface (SEI) film on cyclic performance of Li4Ti5O12 anodes for Li ion batteries

SnO2–graphene–carbon nanotube mixture for anode material with improved rate capacities

A porous cathode material consisting of interconnected single crystal LiNi1/3Co1/3Mn1/3O2 (NCM) nanoparticles has been synthesized for lithium ion batteries. Trace nitric acid is used as pH value adjuster to form honeycomb-shaped foam, and a novel stepwise crystallization process is employed to obtain NCM particles. The modified sol–gel process followed by an optimized crystallization process results in significant improvements in chemical and physical characteristics of the NCM particles. They consist of a fully-developed single crystal NCM with uniform composition and a porous NCM architecture with a reduced degree of fusion and a large specific surface area. These structural modifications in turn significantly enhance the electrochemical properties of the NCM cathode material, in terms of improved charge/discharge capacity, cyclic stability and rate capability.

Microscopically porous, interconnected single crystal LiNi1/3Co1/3Mn1/3O2 cathode material for Lithium ion batteries

Graphene oxide/carbon nanotube (GO/CNT) hybrid films are self-assembled on a Ti substrate via simple casting of aqueous dispersion. The amphiphilic nature of graphene oxide sheets allows adsorption of CNTs onto their surface in water, capable of forming a highly stable dispersion. Binder-free electrodes are prepared using the annealed GO/CNT films for high performance supercapacitors. The hybrid film electrodes with a moderate CNT content, typically 12.5 wt%, give rise to remarkable electrochemical performance with extremely high specific capacitances of 428 and 145 F g−1 at current densities of 0.5 and 100 A g−1, respectively, as well as a remarkable retention rate of 98% of the initial value after 10 000 charge/discharge cycles. The synergistic effects arising from (i) the enlarged surface area of electrodes due to the intercalation of CNTs between the stacked GO sheets with associated large electrochemical active sites and (ii) the improved conductivity through the formation of a 3D network aided by CNTs are mainly responsible for these findings.

Zhen Dong Huang

Papers

Effect of solid electrolyte interface (SEI) film on cyclic performance of Li4Ti5O12 anodes for Li ion batteries

SnO2–graphene–carbon nanotube mixture for anode material with improved rate capacities

Microscopically porous, interconnected single crystal LiNi1/3Co1/3Mn1/3O2 cathode material for Lithium ion batteries

Self-assembled reduced graphene oxide/carbon nanotube thin films as electrodes for supercapacitors

Effects of reduction process and carbon nanotube content on the supercapacitive performance of flexible graphene oxide papers