Abstract: To increase the energy density of a secondary battery, minimize the possibility of fire and explosion, and minimize the dendrite formation problem, provided is a secondary battery, which includes a cathode material and an anode material, wherein the anode material includes an anode structure that is a sheet in which a plurality of yarns formed of carbon nanotube (CNT) fibers are woven.

Abstract: A porous polyurethane sheet includes a urethane polyol prepolymer having an easy storing and handling characteristic. The urethane polyol prepolymer is in a semi-solid state or a solid state at room temperature, and includes a urethane functional group on the main chain thereof along with at least two hydroxyl functional groups. The urethane polyol prepolymer is heated to melt, and an isocyanate compound containing an isocyanate functional group for reacting with the hydroxyl functional group, and a urethane curing catalyst are added and stirred at high speed to form mechanically foamed material. Thus formed mechanically foamed material is cooled to room temperature with or without pressure applied to form a porous polyurethane sheet. Thus formed porous polyurethane has good physical and chemical properties.

Abstract: A process for preparing a polyurethane prepolymer containing carboxylic group(s), or both carboxylic group(s) and double bond(s), which comprises the steps of 1) preparing a diol or triol monomer having carboxylic group(s), or having both carboxylic group(s) and double bond(s) by performing an addition reaction of at least one acid anhydride(s) which may contain double bond(s), with at least one triol or tetraol derivative(s) containing three or four hydroxyl groups in a molar ratio from 0.5:1 to 2:1; and then 2) reacting the obtained diol or triol monomer, or their mixture with a polyol and a diisocyanate or a diisocyanate polymer to give polyurethane prepolymer having an NCO content of 0.1 to 30%, is disclosed. In addition, a process for preparing a water-stable aqueous polyurethane dispersion by neutralizing, dispersing, and chain extending the polyurethane prepolymer obtained above is provided.