DEGASSING METHOD DURING INITIAL CHARGE OF LITHIUM SECONDARY BATTERY AND ITS DEGASSING STRUCTURE

• Main Authors: NAGURA HIDEAKI, HARADA YOSHIRO, INAGAKI MINORU, MURATA TOMOYA
• Format: Patent
• Language: English
• Published: 09.04.1999
• Edition: 6
• Subjects: BASIC ELECTRIC ELEMENTS; ELECTRICITY; PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSIONOF CHEMICAL INTO ELECTRICAL ENERGY

PROBLEM TO BE SOLVED: To release a gas generated during initial charge without strictly controlling humidity by injecting an electrolytic solution from an injection mouth provided at the bottom most end of a recessed part formed at a battery can toward inside of the can, mounting a metallic ball to close the injection mouth being fell in the recessed part of the injection mouth by its own weight, performing initial charge, and then fixing the metallic ball by means of resistance welding after completing initial charge. SOLUTION: This is composed of a pan bottom shape recessed part 3 formed roundly at a can lid 1a, an injection port 5 formed concentrically opened at the most bottom end of the recessed part 3, and a metallic ball 4 contained in the recessed part. A sliding surface material 11 that is non-soluble to an electrolytic solution is injected between a periphery of the injection port 5 and the metallic ball 4 so as to return the electrolytic solution that adheres inside of the recessed part 3 to inside a battery can. When an inside pressure becomes to be high by a generated gas during initial charge, the metallic ball 4 rises by the gas to release the gas outside the battery can. After completing the initial charge, the metallic ball 4 is resistance welded between the recessed part 3 to seal. Thereby, an initial charge can be easily performed in a normal working room.