NONAQUEOUS ELECTROLYTE SECONDARY BATTERY AND ELECTROTHERMAL RELAY FOR BATTERY

摘要

PROBLEM TO BE SOLVED: To prevent accidents caused by rising of the temperature or pressure of a nonaqueous electrolyte secondary battery, to cut off and discharge a troubled battery safely and to improve usability by warning abnormality. SOLUTION: A safety device 20 contains a thermally active shape memory alloy 23 and a moving switch 21 inside a port sealing material 14 and an insulating cover 15. A temperature sensitive bar 22 has a sensor part 22a in a battery and the other end thereof is connected to the thermally active shape memory alloy 23 in the safety device 20. When attaching the thermally active shape memory alloy 23 to the temperature sensitive bar 22 is removed due to temperature rise, a moving contact 21a short circuits between upper side contacts 16a and 17a and battery energy is consumed by the discharge circuit of an abnormal cell connected to an electric current limiting resistance 28 of a resister 25 and a luminescent device 26, etc. Therefore, the abnormal cell is cut off from a battery pack and the series circuit of normal batteries that bypasses the abnormal cell is formed. A bimetal or a thermally melt body can be used instead of a shape memory alloy and a bellows or a diaphragm driven by rising gas pressure can be used as well.