TECHNOLOGY FOCUS - ELECTRICAL POWER AND ENERGY - Preferred Component: The pouch type lithium secondary battery further comprises first and second connection leads (140, 145), where the connection leads electrically connect any one of the protection circuit module and the positive temperature coefficient element to any one of the electrode tabs, respectively; and a hard case to contain and protect the secondary battery, exposing contacts on the protection circuit module for charging and discharging of the electrode assembly. The positive temperature coefficient element includes a first conductive layer, a second conductive layer, and a positive temperature coefficient material layer interposed between the conductive layers. Any one of the conductive layers is connected to any one of the connection leads, while the other one of the conductive layers is electrically connected to the junction pad. One end of the positive temperature coefficient element is connected to the junction pad by one of a resistance weld and an ultrasonic weld. The positive temperature coefficient material layer has an infinitely increasing resistance to interrupt the electric current when the temperature in the secondary battery increases above a predetermined value, while becoming conductive to allow the electric current to flow when the temperature is lowered below the predetermined value. The pouch includes a core portion, a thermal fusion-bonding layer formed on a first surface of the core portion, and an insulation layer formed on a second surface of the core portion. The first electrode plate is coated with one of a positive electrode material and a negative electrode active material. The second electrode plate is coated with the other of the positive electrode material and the negative electrode material. The connection leads are L-shape. The positive temperature coefficient material layer is less than 0.3 mm thick. An insulation tape (116) wraps each of the electrode tabs to prevent electric short-circuiting among the first electrode tab, the second electrode tab, and the pouch.Preferred Method: The method further includes inserting the pouch, the electrode tabs, the positive temperature coefficient element, the junction pad, and the protection circuit module in the hard case; and exposing contacts on the protection circuit module for charging and discharging the electrode assembly. The step of sealing the electrode assembly includes coating the first electrode plate with one of the positive electrode active material and the negative electrode active material; coating the second electrode plate with the other of the positive electrode active material and the negative electrode active material; placing the separator between the first and second electrode plates; and extending one of the electrode tabs from each electrode plate.Preferred Material: The conductive layers are made of a material having excellent conductivity.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Material: The junction pad is made of nickel.    TECHNOLOGY FOCUS - POLYMERS - Preferred Material: The positive temperature coefficient material layer is made of a polymer composite; or styrene butadiene rubber to which carbon is added.