Abstract: A secondary battery includes: an electrode assembly including a first electrode plate, a second electrode plate, and a separator; a case accommodating the electrode assembly and having an opening; a cap plate coupled to and sealing the opening in the case; a first terminal plate on the cap plate and electrically connected to the first electrode plate; and a first current collector plate between the first terminal plate and the electrode assembly to electrically connect the first terminal plate to the electrode assembly. The first current collector plate has a first protrusion that passes through the cap plate and is connected to the first terminal plate.

Abstract: A method for diagnosing a battery system includes: determining, by a processor, first and second charge/discharge test environments providing complementary characteristics for performance degradation of the higher-level battery device exhibits by performing a charge/discharge test with respect to the higher-level battery device; performing, by the processor, a charge/discharge test with respect to the lower-level battery device under the first and second charge/discharge test environments to determine whether a test result matches the complementary characteristics under the first and second charge/discharge test environments; and deriving, by the processor, optimal operating conditions of the battery system in which the complementary characteristics under the first and second charge/discharge test environments are removed, upon determining that the test result of the charge/discharge test with respect to the lower-level battery device matches the complementary characteristics under the first and second charge

Abstract: A battery management apparatus includes a sensor, a calculator, and a processor. The sensor detects temperature and current of at least one battery cell of a plurality of battery cells in the battery. The calculator calculates a first degradation capacity based on the detected temperature of the at least one battery cell at every unit time while the vehicle is being driven, and calculates a second degradation capacity using the detected temperature and a state of charge of the at least one battery cell at every unit time while the vehicle is parked. The processor determines a replacement time of the battery by selecting one of the battery cells which has a largest sum of the first and second degradation capacities, and then calculates a state of health of the battery depending on the first and second degradation capacities of the selected one of the battery cells.

Abstract: A battery management apparatus to manage a battery in a vehicle includes a temperature detector that detects a temperature of the battery, a current detector that detects a current of the battery, a calculation unit that calculates a first degradation capacity using the detected temperature of the battery at every unit time while the vehicle is driven and that calculates a second degradation capacity using the detected temperature and state of charge (SOC) of the battery at every unit time while the vehicle is parked, and a determination unit that calculates a state of health (SOH) of the battery using the first and second degradation capacities so as to determine a replacement time of the battery according to the calculated SOH.

Abstract: A rechargeable battery includes an electrode assembly to charge and discharge current, a case accommodating the electrode assembly, a cap plate coupled the case, electrode terminals on the cap plate, the electrode terminals being electrically connected to the electrode assembly, and a thermal pad between a bottom of the case and the electrode assembly.

Abstract: A fuel cell system including: a reformer to convert a fuel into hydrogen; a reformer chamber to contain air heated by the reformer; a fuel cell stack to convert the hydrogen into electricity; a first pump to supply an oxidant to the stack; and a second pump to supply the heated air to the stack, to preheat the stack. The system may also include a controller to control the operation of the system, such that the heated air is not supplied until it reaches a predetermined temperature, and the oxidant is not supplied and the stack is not operated, until the stack reaches a predetermined temperature.

Abstract: A fuel cell system quickly and efficiently preheats a frozen stack. The fuel cell system includes: a reformer which generates a reformate gas by reforming a fuel and is heated by a heat source unit; a stack which generates electricity by electrochemically reacting an oxidizer with hydrogen in the reformate gas; and a fluid flow controller which moves air around the reformer into an area around the stack, and which controls airflow on the basis of a temperature change of the stack, wherein the air is heated by the surface temperature of the reformer.

Abstract: A fuel cell system including: a reformer to convert a fuel into hydrogen; a reformer chamber to contain air heated by the reformer; a fuel cell stack to convert the hydrogen into electricity; a first pump to supply an oxidant to the stack; and a second pump to supply the heated air to the stack, to preheat the stack. The system may also include a controller to control the operation of the system, such that the heated air is not supplied until it reaches a predetermined temperature, and the oxidant is not supplied and the stack is not operated, until the stack reaches a predetermined temperature.