Early Braking of Overwarmed Lithium-Ion Batteries by Shape-Memorized Current Collectors.

In the context of the constant impending energy crisis, the lithium-ion battery as a burgeoning energy storage means is showing extraordinary talents in many energy relevant investigations. However, fire and explosion would probably occur when the battery is encountered with overheating, at which the shrinking of the separator routinely causes an internal short circuit. Herein, we develop a kind of novel shape-memorized current collector (SMCC), which can successfully brake battery thermal runaway at the battery internal overheating status. Unlike traditional current collectors made of commercial copper foils, SMCC is made of a micropatterned shape memory micron-sized film with copper deposition. SMCC displays ideal conductivity at normal temperatures and turns to be insulative at overheating temperatures. Following this principle, the battery consisting of an SMCC can run normally at temperatures lower than 90 °C, while it quickly achieves self-shutdown before the occurrence of battery combustion and explosion.