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Anode ridge structures are fabricated by printing anode pastes having different rheological properties to increase the electrode–electrolyte interfacial area in anode-supported solid oxide fuel cells. Homogeneous anode pastes are prepared by varying solid loadings, then their rheological characteristics are evaluated. It is confirmed that the shear stress at the same shear rate increases with increasing solid loading. The prepared pastes are printed onto flat anode substrates and then the width and height of the printed pastes are observed before and after drying and after sintering. As increasing solid loading in the paste, not only the width and height become smaller and larger, respectively, but also the shrinkage rate of the aspect ratio becomes smaller. Consequently, a large extension of the interfacial area of about 285% is obtained by printing the paste with the solid loading of 80%.

The development of electrode materials which improve both the energy density and cycle life is one of the most challenging issues facing the practical application of sodium-ion batteries today. In this work, FeTiO₃/C nanoparticles are synthesized as negative electrode materials for sodium-ion batteries. The electrochemical performance and charge-discharge mechanism of the FeTiO₃/C negative electrode are investigated in an ionic liquid electrolyte at 90 °C. The FeTiO₃/C negative electrode delivers a high reversible capacity of 403 mAh g⁻¹ at a current rate of 10 mA g⁻¹, and exhibits high rate capability and excellent cycling stability for up to 2000 cycles. The results indicate that FeTiO₃/C is a promising negative electrode material for sodium-ion batteries.

A sodium secondary battery has been constructed by using a nonvolatile and nonflammable Na[FSA]-[C(3)C(1)pyrr][FSA] (FSA = bis(fluorosulfonyl)amide, C(3)C(1)pyrr = N-methyl-N-propylpyrrolidinium) ionic liquid, a NaCrO(2) positive electrode and a Na metal negative electrode. The charge-discharge performance is evaluated over a wide temperature range of −20–90℃. It has been demonstrated that the sodium secondary battery has long cycle lives both at a high temperature of 90℃ and at a low temperature of 0℃. Thus, the ionic liquid-based sodium secondary battery is expected to be a viable alternative to lithium ion battery for many applications.