Industrial Technology Research Institute

Yingjeng James Li

Ping Ping Tsai

M Stanley Whittingham

Jin-Ming Chen

Weir-Mirn Hurng

Yaw Chung Cheung

Chi Chao Wan

Cheng Hsien Hsu

A method for manufacturing a membrane electrode assembly of a fuel cell by solvent pretreatment to the electrolyte membrane of the membrane electrode assembly is disclosed. A prepared electrolyte membrane is soaked in alcohol solvent for pre-expanding the electrolyte membrane at first, a catalyst layer is uniformly coated onto at least one side of the pre-expanded electrolyte membrane, and then the electrolyte membrane is dried for evenly shrinking the electrolyte membrane and the catalyst layer. Finally, the electrolyte membrane with catalyst layers is interposed between two gas diffusion electrodes, and the resulting sheet is pressed with heating to form the membrane electrode assembly.

Method for manufacturing membrane electrode assembly of fuel cell

A method for forming a solid state humidity sensor is disclosed which comprises the steps of: (a) dissolving a tungstate salt into an aqueous solution; (b) adjusting the pH of the aqueous tungstate salt solution to below 8.5; (c) forming one or a pair of electrodes on an insulating substrate; (d) placing the substrate into the pH-adjusted aqueous tungstate salt solution and heating the aqueous solution containing the substrate at temperatures above 70.degree. C. to thereby form a pyrochlore-type crystalline tungsten trioxide film over the electrode or pair of electrodes; and (e) forming another electrode over the pyrochlore-type crystalline tungsten trioxide film if only one electrode is formed during step (c). Alternatively, the pyrochlore-type crystalline tungsten trioxide film can be formed over or between the electrodes by heating the pH-adjusted aqueous tungstate salt solution to cause a precipitation of pyrochlore-type crystalline tungsten trioxide, then screen-printing the pyrochlore-type crystalline tungsten trioxide powder on one or both of the electrodes to thereby form a humidity sensing element. The pyrochlore-type crystalline tungsten trioxide is represented by the general formula of (M.sub.2 O).sub.x WO.sub.3.zH.sub.2 O, in which M is a cation, x is about 0.5, and z, which is the amount of crystalline water contained in the crystal, is typically less than 2.

Solid state humidity sensor

A method for forming a solid state humidity sensor is disclosed which comprises the steps of: (a) dissolving a tungstate salt into an aqueous solution; (b) adjusting the pH of the aqueous tungstate salt solution to below 8.5; (c) forming one or a pair of electrodes on an insulating substrate; (d) placing the substrate into the pH-adjusted aqueous tungstate salt solution and heating the aqueous solution containing the substrate at temperatures above 70.degree. C. to thereby form a pyrochlore-type crystalline tungsten trioxide film over the electrode or pair of electrodes; and (e) forming another electrode over the pyrochlore-type crystalline tungsten trioxide film if only one electrode is formed during step (c). Alternatively, the pyrochlore-type crystalline tungsten trioxide film can be formed over or between the electrodes by heating the pH-adjusted aqueous tungstate salt solution to cause a precipitation of pyrochlore-type crystalline tungsten trioxide, then screen-printing the pyrochlore-type crystalline tungsten trioxide powder on one or both of the electrodes to thereby form a humidity sensing element. The pyrochlore-type crystalline tungsten trioxide is represented by the general formula of(M.sub.2 O).sub.x WO.sub.3.zH.sub.2 O, in which M is a cation, x is about 0.5, and z, which is the amount of crystalline water contained in said crystal, is typically less than 2.

Method of forming solid state humidity sensor

An improved lithium secondary battery using a novel layered titanium phosphate having the formula of TiO(OH)(H.sub.2 PO.sub.4), or LTP, as anode material, and LiCoO.sub.2, LiNiO.sub.2, or other appropriate material, as cathode. A stable operating voltage of 3-volt can be obtained from the resultant lithium secondary battery. The layered titanium phosphate is prepared by first reacting a tetramethylammonium hydroxide (N(CH.sub.3).sub.4 OH) solution containing orthophosphoric acid with titanium dioxide in a low temperature hydrothermal reaction to form a tetramethylammonium form of layered titanium phosphate, or NMe.sub.4 TP, which serves as the precursor of LTP. The precursor NMe.sub.4 TP is then placed in a concentrated hydrochloric acid at room temperature to obtain a high purity LTP via a cation exchange reaction. Each of the Li.sub.x LTP chemical unit, which is formed after the intercalation of LTP with lithium ions, can contain two lithium ions, thus excellent lithium intercalation characteristic can be achieved as a result. Furthermore, no lithium dendrites are formed during the recharging operation which tend to puncture the partition membranae separating the anode and the cathode; therefore, the secondary lithium battery allows a safe recharging operation to be maintained.

Growing community of inventors

Pingtung, Taiwan

Yingjeng James Li