• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.30 no.12
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• pp.788-793
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• 2017

Electrical behaviors of plasma-sprayed $Al_2O_3-TiO_2$ coatings have been investigated in terms of their $TiO_2$ content. On increasing the $TiO_2$ content from 6 to 30 wt%, the DC electrical conductivity increased by several orders of magnitude. From impedance spectroscopy analysis, the total conductivity of the grains and grain boundaries and their respective activation energies were determined without the electrode effects that could impede ionic transfer. An electron transference number was also estimated, ranging between 6.5% and 7.3% for 13 wt% $TiO_2$ and between 0.4% and 0.7% for 30 wt% $TiO_2$ in the coating. Because of the high electronic contribution to the total conductivity, the $Al_2O_3-TiO_2$ coating could be a new candidate material to obtain superior electrical conductivity as well as corrosion and wear resistances.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.11 no.9
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• pp.733-738
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• 1998

본 논문에서는 고체 리듐 전지를 개발하기 위하여 poly(ethylene oxide) [PEO] 에 $LiClO_4$, poly (vinylidene fluoride) [PVDF] 및 가소제로 propylene carbonate [PC] 와 ethylene carbonate[EC] 등을 혼합여 고분자 저해질을 제조하였다. 또한 고체 리듐 전지용 정극으로써 우수한 특성이 기대되는 $Li_xV_3O_8$을 졸-겔법에 의해 합성하여 $Li_xV_3O_8$SPE/Li cell 의 전기화학적 특성을 측정하였다. 고분자 matrix는 PEO와 PVDE를 혼합 사용한 결과 $PEO_4 PVDF_4LiCIO_4PC_5EC_5$ 고분자 전해질이 상온에서 $5.2 {\times} 10{-3}$ S/cm 의 높은 이온 전도도를 나타냈으며 리듐 이온 transference number는 0.3이었다. 졸-겔법에 의해 제조된 $Li_xV_3O_8$을 사용한 $Li_xV_3O_8$SPE/Li cell의 방전시 cell 저항이 방전 초기에는 비소한 증가를 하다가 방전 말기 전압인 2.0V에서 크게 증가하였다. $Li_xV_3O_8$ composite 정극의 첫 번째 방전 용량은 295㎃h/g이었으며 8번째 충방전 싸이클부터 방전 용량이 안정화 되었고 15번째 방전 용량도 212㎃h/g으로 고체 전지용 정극으로써 우수한 특성을 보였다.

• Journal of the Korean Ceramic Society
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• v.53 no.6
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• pp.635-640
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• 2016

Electrical behavior of AlN ceramics sintered with $Y_2O_3$ as a sintering aid has been investigated with respect to additional $TiO_2$ dopant. From the impedance spectroscopy, it was found that the grain and grain boundary conductivities have greatly decreased with addition of $TiO_2$ dopant. The $TiO_2$ dopant also increased the activation energy of the grain conductivity by about 0.37 eV; this increase was attributed to the formation of an associate between Al vacancies and Ti ions at the Al sites. Similarly, the electronic conductivity was reduced by $TiO_2$ addition. However, $TiO_2$ solubility in AlN grains was below the detection limit of typical EDX analysis. Grain boundary was clean, without liquid films, but did show yttrium segregation. The transference number of ions was close to 1, showing that AlN is a predominantly ionic conductor. Based on the observed results, the implications of using AlN applications as insulators have been discussed.