In order to improve the power performance of the lithium ion battery based on lithium iron phosphate (LiFePO4), a new methodology using a three-dimensional micro-porous current collector was described. The three-dimensional current collector was manufactured based on foamed polyurethane and nickel–chromium alloy. The cell using the three-dimensional current collector exhibited a superior high-rate discharge capability as compared to a conventional-type cell using the aluminum foil current collector. Furthermore, impedance analysis revealed the size reduction of a semicircle for the charge-transfer resistance by applying the three-dimensional current collector, which indicates a superior current collecting ability for the developed substrate.