Patent ID: 7737661
Filing Date: 2010-06-15
Classification: H01M,Y02E

Abstract:
1. A secondary battery comprising: a constant-voltage device connected directly between a cathode and an anode of the secondary battery in a row, wherein the constant-voltage device is the only element in between the cathode and the anode; a breakdown voltage of the constant-voltage device is lower than an explosion/ignition voltage of the secondary battery and a leakage current value of the constant-voltage device is less than 0.05% of a capacity value, which is expressed with a unit of “current×hour”, of the secondary battery under a maximum charge voltage of the secondary battery; when the voltage of the secondary battery rises exceeding the breakdown voltage of the constant-voltage device, the resistance of the constant-voltage device drops near to zero, and a current flows through the constant-voltage device between the cathode and the anode discharging the secondary battery substantially in a short circuit state; wherein the breakdown voltage of the constant-voltage device is in a range of 5 to 20V; and the maximum charge voltage of the secondary battery is 4.2V or less.