A high performance hybrid battery based on aluminum anode and LiFePO4 cathode.

A novel hybrid battery utilizing an aluminum anode, a LiFePO4 cathode and an acidic ionic liquid electrolyte based on 1-ethyl-3-methylimidazolium chloride (EMImCl) and aluminum trichloride (AlCl3) (EMImCl-AlCl3, 1-1.1 in molar ratio) with or without LiAlCl4 is proposed. The hybrid ion battery delivers an initial high capacity of 160 mA h g(-1) at a current rate of C/5. It also shows good rate capability and cycling performance.

Hybrid Lithium-Sulfur Batteries with a Solid Electrolyte Membrane and Lithium Polysulfide Catholyte.

Lithium-sulfur (Li-S) batteries are receiving great attention as the most promising next-generation power source with significantly high charge-storage capacity. However, the implementation of Li-S batteries is hampered by a critical challenge because of the soluble nature of the intermediate polysulfide species in the liquid electrolyte. The use of traditional porous separators unavoidably allows the migration of the dissolved polysulfide species from the cathode to the lithium-metal anode and results in continuous loss of capacity. In this study, a LiSICON (lithium super ionic conductor) solid membrane is used as a cation-selective electrolyte for lithium-polysulfide (Li-PS) batteries to suppress the polysulfide diffusion. Ionic conductivity issue at the lithium metal/solid electrolyte interface is successfully addressed by insertion of a "soft", liquid-electrolyte integrated polypropylene interlayer. The solid LiSICON lithium-ion conductor maintains stable ionic conductivity during the electrochemical cycling of the cells. The Li-PS battery system with a hybrid solid/liquid electrolyte exhibits significantly enhanced cyclability relative to the cells with the traditional liquid-electrolyte integrated porous separator.

Polymeric molecular sieve membranes via in situ cross-linking of non-porous polymer membrane templates.

High-performance polymeric membranes for gas separation are attractive for molecular-level separations in industrial-scale chemical, energy and environmental processes. Molecular sieving materials are widely regarded as the next-generation membranes to simultaneously achieve high permeability and selectivity. However, most polymeric molecular sieve membranes are based on a few solution-processable polymers such as polymers of intrinsic microporosity. Here we report an in situ cross-linking strategy for the preparation of polymeric molecular sieve membranes with hierarchical and tailorable porosity. These membranes demonstrate exceptional performance as molecular sieves with high gas permeabilities and selectivities for smaller gas molecules, such as carbon dioxide and oxygen, over larger molecules such as nitrogen. Hence, these membranes have potential for large-scale gas separations of commercial and environmental relevance. Moreover, this strategy could provide a possible alternative to 'classical' methods for the preparation of porous membranes and, in some cases, the only viable synthetic route towards certain membranes.

Studies on supercapacitor electrode material from activated lignin-derived mesoporous carbon.

We synthesized mesoporous carbon from pre-cross-linked lignin gel impregnated with a surfactant as the pore-forming agent and then activated the carbon through physical and chemical methods to obtain activated mesoporous carbon. The activated mesoporous carbons exhibited 1.5- to 6-fold increases in porosity with a maximum Brunauer-Emmett-Teller (BET) specific surface area of 1148 m(2)/g and a pore volume of 1.0 cm(3)/g. Both physical and chemical activation enhanced the mesoporosity along with significant microporosity. Plots of cyclic voltammetric data with the capacitor electrode made from these carbons showed an almost rectangular curve depicting the behavior of ideal double-layer capacitance. Although the pristine mesoporous carbon exhibited a range of surface-area-based capacitance similar to that of other known carbon-based supercapacitors, activation decreased the surface-area-based specific capacitance and enhanced the gravimetric specific capacitance of the mesoporous carbons. A vertical tail in the lower-frequency domain of the Nyquist plot provided additional evidence of good supercapacitor behavior for the activated mesoporous carbons. We have modeled the equivalent circuit of the Nyquist plot with the help of two constant phase elements (CPE). Our work demonstrated that biomass-derived mesoporous carbon materials continue to show potential for use in specific electrochemical applications.

Orienting oxygen vacancies for fast catalytic reaction.

A strategy to enhance the catalytic activity at the surface of an oxide thin film is unveiled through epitaxial orientation control of the surface oxygen vacancy concentration. By tuning the direction of the oxygen vacancy channels (OVCs) in the brownmillerite SrCoO2.5 , a 100-fold improvement in the oxygen reduction kinetics is realized in an epitaxial thin film that has the OVCs open to the surface.

Highly dispersed sulfur in a porous aromatic framework as a cathode for lithium-sulfur batteries.

Lithium-sulfur (Li-S) batteries are attractive candidates for transportation applications because of their high energy density (2600 W h kg(-1)). However, Li-S batteries have failed to achieve commercial success, due to the rapid capacity fading with cycling caused mainly by the "shuttle" phenomenon. Here, we report a feasible approach to mitigate this issue using a porous aromatic framework (PAF) as a hosting substrate in Li-S batteries. As a cathode material, the composite of PAF with sulfur exhibits high capacity and excellent cycling stability in both a sulfone electrolyte, 1.0 M LiPF6-MiPS, and an ionic liquid electrolyte, 0.5 M LiTFSI-MPPY·TFSI.