Abstract: A secondary battery includes a first electrode, a second electrode, an ion transmission member in contact with the first electrode and the second electrode, and a hole transmission member in contact with the first electrode and the second electrode. Suitably, the first electrode contains a composite oxide. The composite oxide contains alkali metal or alkali earth metal. The composite oxide contains a p-type composite oxide as a p-type semiconductor.

Abstract: A secondary battery includes a positive electrode and a negative electrode. The negative electrode includes a layered material with an interlayer distance of 10 nm to 500 nm and interlayer particles with a diameter of smaller than 1 ?m arranged among layers of the layered material.

Abstract: A secondary battery includes: a negative electrode; a positive electrode containing a p-type semiconductor material; and an isolation layer configured to isolate the negative electrode from the positive electrode and including a hole transmission member. The isolation layer is layered by being applied to at least one of the negative electrode and the positive electrode. Preferably, the hole transmission member contains ?-alumina. Preferably, the isolation layer includes the same binding agent as the negative electrode or the positive electrode.

Abstract: A positive electrode active material includes: center cores containing a composite oxide containing alkali metal or alkali earth metal; and eutectic layers containing a eutectic substance composed of at least two types of composite oxides containing the alkali metal or the alkali earth metal and configured to cover the center cores. Preferably, the eutectic layers have a thickness of 4 nm or larger and 800 nm or smaller. The composite oxides forming the eutectic substance include the composite oxide of the center cores.

Abstract: A secondary battery includes a positive electrode and a negative electrode. The negative electrode includes first particles made of metal and second particles made of a silicon containing substance. The first particles are in contact with the second particles.

Abstract: An auxiliary binocular device for astronomical telescope, comprising a center tube, a left lens unit, a right lens unit and a beam splitter and image-inverting device, the objective lens of the binocular device being joined to the eyepiece of astronomical telescope, so the telescope becomes binocular. The beam splitter and image-inverting device is installed inside the center tube, the right lens unit and the left lens unit, comprising a beam splitter prism, three reflected mirrors and two lens sets, having beam splitting and image-inverting functions.