Abstract: A secondary battery includes positive and negative electrode terminals spaced apart on a first face of a hexahedral-shaped battery case, a nonlinear terminal body contacting the first face of the battery case and a side of the battery case extending from the first face of the battery case while enclosing one of the positive or negative electrode terminals, a terminal structure including an extension terminal electrically connected to the one of the positive or negative electrode terminals, and the extension terminal exposed on a side of the terminal structure, wherein the side of the terminal structure is seated in a recessed surface formed in the side of the battery case.

Abstract: A negative electrode for a lithium secondary battery includes: a negative electrode active layer provided on at least one surface of a negative electrode current collector, and including a negative electrode active material; and a coating layer disposed on the negative electrode active layer. The coating layer contains silicon-containing particles, aluminum-containing particles and a dispersant, and a volume resistance of the coating layer is about 1.0×10?4 ?·cm to 1.0 ?·cm.

Abstract: A negative electrode for a lithium secondary battery includes: a negative electrode active layer provided on at least one surface of a negative electrode current collector, and including a negative electrode active material; and a coating layer disposed on the negative electrode active layer. The coating layer contains silicon-containing particles, aluminum-containing particles and a dispersant, and a volume resistance of the coating layer is about 1.0×10?4 ?·cm to 1.0 ?·cm.

Abstract: A lithium secondary battery includes: a positive electrode, a negative electrode, and a separator disposed between the positive electrode and the negative electrode. In the negative electrode, a negative electrode active layer containing a carbon-based negative electrode active material and a coating layer containing silicon-containing particles are sequentially located on a negative electrode current collector, and a volume resistance of the negative electrode is about 6.0×10?3 ?·cm to 1.0 ?·cm.

Abstract: A method for making an optical fiber preform having an ultimately low PMD (Polarization Mode Dispersion) through improvement of ovality is provided. This method has several collapse steps for collapsing an optical fiber preform having a clad/core deposition layer formed in a preform tube in which a rate of collapse is 0.01-0.06 mm/min at each collapsing step. By using this method, ovality and PMD of the optical fiber preform may be improved.