To reduce or prevent the breakage or firing of a battery even when a physical impact is added to a battery can in charging sate by peeling a current collector from an electrode when an electrolyte is raised to a specified temperature range.
A nonaqueous electrolyte secondary battery is constituted in such a manner that a positive electrode and a negative electrode are at least partially peeled from a current collector within an electrolyte temperature range of 60-120°C. For this, a binder such as fluorine-contained resin is contained in the positive electrode and the negative electrode in an amount of about 0.5-10wt.%, and when the electrolyte is raised to 60°C or more, the current collector is peeled from the electrode bodies. As a peeling accelerator, an inorganic or organic foaming agent is contained in the battery. The foaming agent generates a gas at an electrolyte temperature of 60°C or more to peel the electrode materials from the current collector. Thus, since the flow of electron or ion is arrested to make the current hard to flow, the rise of internal pressure by boiling of the electrolyte or thermal runaway of an active material can be suppressed.
NAKAE TAKEJI
MATSUDA YOSHIO
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