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Novel composite gel polymer electrolytes exhibiting high ionic conductivity and good mechanical stability are prepared, and their electrochemical properties are characterized. As lithium ion sources of a single ion conductor, the core‐shell structured SiO2(Li+) nanoparticles with uniform spherical shape are synthesized and used as functional fillers in the composite gel polymer electrolytes. By using the composite gel polymer electrolytes, the lithium powder polymer batteries composed of a lithium powder anode and a layered lithium vanadate (LiV3O8) cathode are assembled and their cycling performance is evaluated. The resulting lithium powder polymer batteries deliver a high discharge capacity of 264 mAh g−1 at room temperature and exhibit good capacity retention even at high current rates. The morphological analysis of the lithium powder anode reveals that the dendrite growth during cycling can be effectively suppressed by using the composite gel polymer electrolytes.

The nanocomposites of polypyrrole (PPy) and multi-walled carbon nanotube (MWCNT) with different composition are synthesized by the chemical oxidative polymerization method. In these composites, the MWCNTs are uniformly coated by PPy with different thickness. The electrochemical properties of the composite electrodes are investigated by cyclic voltammetry, galvanostatic charge-discharge cycling and electrochemical impedance spectroscopy. The full cells assembled with the PPy/MWCNT composite electrodes deliver initial specific capacitances ranging from 146.3 to 167.2 F/g at 0.5 mA/cm 2 and exhibit stable cycling characteristics. The effect of content of MWCNT in the composite on cycling performance of the cells is also investigated.

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We studied the microstructural and electrochemical properties of Ti-doped Al2O3 (Ti-Al2O3) coated LiCoO2 thin films depending on the Ti composition. The 1.27 at.% Ti-Al2O3 coated films had an amorphous structure with better conductivity than that of pure Al2O3 films. The Ti-Al2O3 coating layer effectively suppressed the dissolution of Co and the formation of lower Li conductivity SEI films at the interface between the LiCoO2 film and electrolyte. The Ti-Al2O3 coating improved the cycling performance and capacity retention at high voltage (4.5 V) of the LiCoO2 films. The Ti-Al2O3 coated LiCoO2 films showed better electrochemical properties than did the pure Al2O3 coated LiCoO2 films. These results were closely related to the enhanced Li-conductivity and interfacial quality of the Ti-Al2O3 film.