LITHIUM-ION SECONDARY-BATTERY CASE AND MANUFACTURING METHOD THEREFOR

摘要

This invention provides a lithium-ion secondary-battery case, and a manufacturing method therefor, that can be joined with no weld spatter and is strong with respect to external forces acting on said case. Said case is characterized in that: a cup component (2) comprises an austenite stainless-steel foil; a cap component (3) comprises a two-phase stainless steel that exhibits an austenite start temperature Ac1 between 650°C and 950°C during a temperature-raising process and has an austenite-ferrite two-phase temperature region starting at 880°C; said components are placed in direct contact with each other; and in a heating-temperature range of 880-1080°C, diffusion bonding is performed, accompanied by grain-boundary migration as the ferrite phase of the two-phase steel transforms into an austenite phase.