Rechargeable quasi-solid state lithium battery with organic crystalline cathode.

Utilization of metal-free low-cost high-capacity organic cathodes for lithium batteries has been a long-standing goal, but critical cyclability problems owing to dissolution of active materials into the electrolyte have been an inevitable obstacle. For practical utilisation of numerous cathode-active compounds proposed over the past decades, a novel battery construction strategy is required. We have designed a solid state cell that accommodates organic cathodic reactions in solid phase. The cell was successful at achieving high capacity exceeding 200 mAh/g with excellent cycleability. Further investigations confirmed that our strategy is effective for numerous other redox-active organic compounds. This implies hundreds of compounds dismissed before due to low cycleability would worth a re-visit under solid state design.

Mechanistic studies of AFM probe-driven Suzuki and Heck molecular coupling.

The initiation and high resolution control of surface confined chemical reactions would be both beneficial for nanofabrication and fundamentally interesting. In this work, mechanistic aspects of spatially confined Suzuki and Heck 'catalytic nanolithography' are investigated by varying the experimental parameters and noting their effects on apparent reactivity and lithographic yield. A variety of molecular couplings can be driven by the activated scanning probe with linewidths ultimately limited by its functional apex. On ramping the speed at which the probe traverses the surface confined reagent, one reaches a limit where the catalytic chemistry becomes limiting and reaction rates can be estimated. Self-assembled monolayer (SAM) confined bromide reagents are observed to be more labile than their iodide analogues in Suzuki couplings. With Heck reactions, coupling rates are observed to be faster with the styrene surface confined than in the 'inverted configuration' with an aryl halide SAM, possibly because the accepted (solution phase) rate-determining step is bypassed in the former configuration. For both Heck and Suzuki coupling reactions, calculations indicate that catalyst turnover numbers per nanoparticle are an order of magnitude or more greater within the confines of the AFM probe-surface junction compared to solution phase reactions. A PVP matrix model is presented to account for these observations and the mechanism of catalytic nanolithography.

Spatially controlled Suzuki and Heck catalytic molecular coupling.

The initiation and control of chemical coupling has the potential to offer much within the context of "bottom up" nanofabrication. We report herein the use of a palladium-modified, catalytically active, AFM probe to initiate and spatially control surface-confined Suzuki and Heck carbon-carbon coupling reactions. These "chemically written reactions", detectable by lateral force and chemically specific optical and topographic labeling, were patterned with line widths down to 15 nm or approximately 20 molecules. Catalyzed organometallic coupling was, in this way, carried out at subzeptomolar levels. By varying the catalyst-substrate interaction times, turnover numbers of (0.6-1.2) x 10(4) and (3.0-5.0) x 10(4) molecules s(-1) were resolved for Suzuki and Heck reactions, respectively.