AlPO 4 "-coated LiCoO 2 was shown to exhibit markedly improved capacity retention relative to bare LiCoO 2 upon cycling to 4.7 V. Scanning and transmission electron microscopy imaging showed that the coating thickness of "AlPO 4 "-coated LiCoO 2 varied from ∼10 to ∼100 nm. Energy-dispersive X-ray mapping revealed that the coating was not single-phase "AlPO 4 ", rather consisting of P-rich thick regions (∼100 nm) and Al-rich thin regions (∼10 nm). Detailed X-ray photoelectron spectroscopy (XPS) studies of the "AlPO 4 "-coated LiCoO 2 in comparison to bare LiCoO 2 and various reference compounds such as Li 2 CO 3 , Li 3 PO 4 , and AlPO 4 indicate that (1) AlPO 4 is absent on the surface; (2) the surface consisted of Li 3 PO 4 and heavily Al substituted LiAl y Co 1-y O 2 , which may result from AlPO 4 nanoparticles reacting with bare LiCoO 2 during the coating heat treatment at 700°C; and (3) the amount of surface Li 2 CO 3 is markedly reduced in the coated sample relative to the bare LiCoO 2 . The existence of Li 3 PO 4 in "AlPO 4 "-coated LiCoO 2 was confirmed with X-ray powder diffraction. The coating microstructure of "AlPO 4 "-coated LiCoO 2 is proposed, and the mechanisms of enhancement in the cycling and thermal characteristics by particle surface microstructure are discussed in detail.

A new procedure is described for surface grafting polymer brushes by step-growth polymerization from initiator-embedded polymeric thin films and micron- and nanometer-scale patterns. An imprint lithographic process, nanocontact molding, was used to prepare thin patterned cross-linked polyacrylate network films on silicon wafers that incorporated 4-bromostyrene in the networks. These networks present reactive 4-bromophenyl functionality at the surface that act as attachment sites for the subsequent Ni(0)- mediated step-growth condensation polymerization of 2,7-dibromo-9,9-dihexylfluorene The step-growth polymerization medium consisted of 2,7-dibromo-9,9-dihexylfluorene, Ni(0)-catalyst, and bipyridine in a toluene/dimethylformamide solvent mixture. The resulting growth of polydihexylfluorene brushes from the patterned surface was monitored by contact angle, optical spectrometry, surface profilometry and AFM. Brush growth was conducted from patterned features ranging from 100 microm to 100 nm in width and 50 nm in height. The optical and fluorescence behavior of the polyfluorene brushes was similar to that of thin polyfluorene films made by spin coating.

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