SciCombinator

Discover the most talked about and latest scientific content & concepts.

Concept: Lithium-ion polymer battery

193

Current lithium batteries operate on inorganic insertion compounds to power a diverse range of applications, but recently there is a surging demand to develop environmentally friendly green electrode materials. To develop sustainable and eco-friendly lithium ion batteries, we report reversible lithium ion storage properties of a naturally occurring and abundant organic compound purpurin, which is non-toxic and derived from the plant madder. The carbonyl/hydroxyl groups present in purpurin molecules act as redox centers and reacts electrochemically with Li-ions during the charge/discharge process. The mechanism of lithiation of purpurin is fully elucidated using NMR, UV and FTIR spectral studies. The formation of the most favored six membered binding core of lithium ion with carbonyl groups of purpurin and hydroxyl groups at C-1 and C-4 positions respectively facilitated lithiation process, whereas hydroxyl group at C-2 position remains unaltered.

Concepts: Functional group, Battery, Rechargeable battery, Carbohydrate, Lithium-ion battery, Lithium, Lithium battery, Lithium-ion polymer battery

175

One of the most exciting areas in lithium ion batteries is engineering structured silicon anodes. These new materials promise to lead the next generation of batteries with significantly higher reversible charge capacity than current technologies. One drawback of these materials is that their production involves costly processing steps, limiting their application in commercial lithium ion batteries. In this report we present an inexpensive method for synthesizing macroporous silicon particulates (MPSPs). After being mixed with polyacrylonitrile (PAN) and pyrolyzed, MPSPs can alloy with lithium, resulting in capacities of 1000 mAhg(-1) for over 600+ cycles. These sponge-like MPSPs with pyrolyzed PAN (PPAN) can accommodate the large volume expansion associated with silicon lithiation. This performance combined with low cost processing yields a competitive anode material that will have an immediate and direct application in lithium ion batteries.

Concepts: Electron, Cathode, Battery, Electrolysis, Lithium-ion battery, Lithium, Lithium battery, Lithium-ion polymer battery

169

We demonstrate a simple, efficient, yet versatile strategy for the synthesis of novel hierarchical heterostructures composed of TiO(2) nanofiber stem and various metal oxides (MOs) secondary nanostructures, including Co(3)O(4), Fe(2)O(3), Fe(3)O(4), and CuO, by advantageously combining the versatility of the electrospinning technique and hydrothermal growth method, for which the controllable formation process and possible formation mechanism are also investigated. Moreover, as a proof-of-concept demonstration of the functional properties of these hierarchical heterostructures, the Co(3)O(4)/TiO(2) hierarchical heterostructures are investigated as the lithium-ion batteries (LIBs) anode materials for the first time, which not only delivers a high reversible capacity of 632.5 mAh g(-1) and 95.3% capacity retention over 480 cycles, but also shows excellent rate capability with respect to the pristine TiO(2) nanofibers. The synergetic effect between Co(3)O(4) and TiO(2) as well as the unique feature of hierarchical heterostructures are probably responsible for the enhanced electrochemical performance.

Concepts: Battery, Rechargeable battery, Lithium-ion battery, Lithium, Lithium battery, Lithium-ion polymer battery, Electric car, Lithium-ion batteries

43

Lattice oxygen can play an intriguing role in electrochemical processes, not only maintaining structural stability, but also influencing electron and ion transport properties in high-capacity oxide cathode materials for Li-ion batteries. Here, we report the design of a gas-solid interface reaction to achieve delicate control of oxygen activity through uniformly creating oxygen vacancies without affecting structural integrity of Li-rich layered oxides. Theoretical calculations and experimental characterizations demonstrate that oxygen vacancies provide a favourable ionic diffusion environment in the bulk and significantly suppress gas release from the surface. The target material is achievable in delivering a discharge capacity as high as 301 mAh g(-1) with initial Coulombic efficiency of 93.2%. After 100 cycles, a reversible capacity of 300 mAh g(-1) still remains without any obvious decay in voltage. This study sheds light on the comprehensive design and control of oxygen activity in transition-metal-oxide systems for next-generation Li-ion batteries.

Concepts: Cathode, Oxygen, Oxide, Ion, Rechargeable battery, Lithium-ion battery, Lithium, Lithium-ion polymer battery

28

The other polymorph: A vapor-phase route for the fabrication of β-Fe(2) O(3) nanomaterials on Ti substrates at 400-500 °C is reported. For the first time, the β polymorph is tested as anode for lithium batteries, exhibiting promising performances in terms of Li storage and rate capability.

Concepts: Battery, Electrolysis, Rechargeable battery, Lithium-ion battery, Lithium, Lithium battery, Lithium-ion polymer battery, Nanowire battery

28

Porous SnO(2)/graphene composite thin films are prepared as anodes for lithium ion batteries by the electrostatic spray deposition technique. Reticular-structured SnO(2) is formed on both the nickel foam substrate and the surface of graphene sheets according to the scanning electron microscopy (SEM) results. Such an assembly mode of graphene and SnO(2) is highly beneficial to the electrochemical performance improvement by increasing the electrical conductivity and releasing the volume change of the anode. The novel engineered anode possesses 2134.3 mA h g(-1) of initial discharge capacity and good capacity retention of 551.0 mA h g(-1) up to the 100th cycle at a current density of 200 mA g(-1). This anode also exhibits excellent rate capability, with a reversible capacity of 507.7 mA h g(-1) after 100 cycles at a current density of 800 mA g(-1). The results demonstrate that such a film-type hybrid anode shows great potential for application in high-energy lithium-ion batteries.

Concepts: Electron, Rechargeable battery, Lithium-ion battery, Lithium, Lithium battery, Lithium-ion polymer battery, Electric car, Nickel-metal hydride battery

27

Silicon (Si) nanomaterials have emerged as a leading candidate for next generation lithium-ion battery anodes. However, the low electrical conductivity of Si requires the use of conductive additives in the anode film. Here we report a solution-based synthesis of Si nanowires with a conductive carbon skin. Without any conductive additive, the Si nanowire electrodes exhibited capacities of over 2000 mA h g-1 for 100 cycles when cycled at C/10 and over 1200 mA h g-1 when cycled more rapidly at 1C against Li metal. In situ transmission electron microscopy (TEM) observation reveals that the carbon skin performs dual roles: it speeds lithiation of the Si nanowires significantly, while also constraining the final volume expansion. The present work sheds light on ways to optimize lithium battery performance by smartly tailoring the nanostructure of composition of materials based on silicon and carbon.

Concepts: Electron, Battery, Rechargeable battery, Lithium-ion battery, Lithium, Lithium battery, Lithium-ion polymer battery, Nanowire battery

27

A Si/graphene composite is drop-casted on an ultrathin-graphite foam (UGF) with three dimensional conductive network. The Si/graphene/UGF composite presents excellent stability and relatively high overall capacity when tested as an anode for rechargeable lithium ion batteries.

Concepts: Rechargeable battery, Lithium-ion battery, Lithium, Lithium battery, Lithium-ion polymer battery, Nanowire battery, Nickel-metal hydride battery, Nickel-cadmium battery

27

Down to the wire: Three-dimensional interconnected Si-based nanowires are produced through the combination of thermal decomposition of SiO and a metal-catalyzed nanowire growth process. This low-cost and scalable approach provides a promising candidate for high-capacity anodes in lithium-ion batteries.

Concepts: Nanowire, Rechargeable battery, Lithium-ion battery, Lithium-ion polymer battery, Nanowire battery, Nickel-metal hydride battery, Nickel-cadmium battery, Lithium iron phosphate battery

27

Watch your figure: Three different shapes of TiO2 nanoparticles with various exposed facets have been synthesized by changing the adsorbents. The spindly octahedron with exposed high-index {401} facet exhibit the highest electrochemical performance than that of the other shapes.

Concepts: Titanium dioxide, Diamond, Rechargeable battery, Lithium-ion battery, Lithium-ion polymer battery, Octahedron, Lithium-ion batteries, Facet