Nanocrystalline <mml:math display="inline"><mml:msub><mml:mi mathvariant="normal">LiFePO</mml:mi><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub></mml:math>LiFePO4 was obtained by heating amorphous nanosized <mml:math display="inline"><mml:msub><mml:mi mathvariant="normal">LiFePO</mml:mi><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub><mml:mo>.</mml:mo></mml:math>LiFePO4. The amorphous material was obtained by lithiation of <mml:math display="inline"><mml:msub><mml:mi mathvariant="normal">FePO</mml:mi><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub></mml:math>FePO4 synthesized by spontaneous precipitation from equimolar aqueous solutions of <mml:math display="inline"><mml:mi mathvariant="normal">Fe</mml:mi><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mo>NH</mml:mo><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mo stretchy="false">)</mml:mo><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo stretchy="false">(</mml:mo><mml:msub><mml:mo>SO</mml:mo><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mo stretchy="false">)</mml:mo><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>⋅</mml:mo><mml:mn>6</mml:mn><mml:msub><mml:mo>H</mml:mo><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:mo>O</mml:mo></mml:math>Fe(NH4)2(SO4)2⋅6H2O and <mml:math display="inline"><mml:msub><mml:mo>NH</mml:mo><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mo>H</mml:mo><mml:mrow><mml:mn>2</mml:mn></mml:mrow></mml:msub><mml:msub><mml:mo>PO</mml:mo><mml:mrow><mml:mn>4</mml:mn><mml:mo>,</mml:mo></mml:mrow></mml:msub></mml:math>NH4H2PO4, using hydrogen peroxide as the oxidizing agent. The materials were characterized by chemical analysis, thermogravimetric and differential thermal analysis, X-ray powder diffraction, and scanning electron microscopy. The Brunauer- Emmett-Teller method was used to evaluate the specific surface area. Nanocrystalline <mml:math display="inline"><mml:msub><mml:mi mathvariant="normal">LiFePO</mml:mi><mml:mrow><mml:mn>4</mml:mn></mml:mrow></mml:msub></mml:math>LiFePO4 showed very good electrochemical performance delivering about the full theoretical capacity <mml:math display="inline"><mml:mo stretchy="false">(</mml:mo><mml:mn>170</mml:mn><mml:mo> </mml:mo><mml:msup><mml:mi mathvariant="normal">Ah kg</mml:mi><mml:mrow><mml:mo>−</mml:mo><mml:mn>1</mml:mn></mml:mrow></mml:msup><mml:mo stretchy="false">)</mml:mo></mml:math>(170 Ah kg−1) when cycled at the C/10 rate. A capacity fade of about 0.25% per cycle affected the material upon cycling. © 2002 The Electrochemical Society. All rights reserved.

The investment casting process is widely used in the aerospace industry to produce complex engine parts. The article determines the properties of quartz powders, nanosilica dioxide binders, and multilayer samples of ceramic casting molds. The properties of spherical molds obtained using an alcohol-water system derived from hydrolyzed ethyl silicate (ZKE) and LUDOX PX-30 (type Q1) were compared with those obtained in water systems derived from Remasol Plus and Remasol Premium binders (type Q2). The spherical samples are composed of seven layers made with the use of an immersion-sprinkling method. To assess the properties of the molds, X-ray microscopy (µCT), scanning electron microscopy (SEM), and gas permeability analysis over a temperature range of 20–950 °C were utilized. The binder type is proven to affect the properties of the casting mold samples. The material obtained in the water system, Q2, has advantageous properties such as a high porosity and gas permeability.