Polyimide/Ionic Crystal-Based Hybrid Electrolyte for a Self-Powered Multistage Fire Alarm

Fire seriously threatens human life and causes a large
number of
losses. Common fire alarms are composed of sensors and power supply,
but damage of any components at high temperatures will lead to their
failure, which poses a challenge to the application of stable and
sensitive alarms in an extreme environment. Hence, we report a nonflammable
self-powered alarm, which integrates energy supply and a multistage
sensor. The self-powered alarm is a thermal-responsive smart supercapacitor
composed of high-temperature-resistant polyimide nanofibers and ionic
crystals. Thanks to the sharp conductivity change (more than 3 orders
of magnitude) of the ionic crystal at the phase transition point,
the self-powered alarm shows stable energy storage performance at
room temperature (maintained a high potential of above 1.3 V) and
sensitive temperature response in a fire. Furthermore, due to the
structural designability of the ionic crystal, the phase transition
point can be adjusted according to demand (e.g., 40, 60, and 90 °C).
Therefore, the polyimide/ionic crystal-based self-powered alarm can
achieve a multistage fire alarm based on temperature. These unique
properties of a self-powered smart alarm will effectively reduce the
loss caused by fire and protect human life.

火灾严重威胁人类生命安全，并造成巨额财产损失。常规火灾报警器多由传感器与供电单元组成，但高温环境下任意组件失效都会导致报警器失灵，这为稳定且灵敏的报警器在极端环境中的应用带来了挑战。为此，本研究报道了一款集成了供能单元与多级传感器的不燃型自供电火灾报警器。该自供电报警器为热响应型智能超级电容器，由耐高温聚酰亚胺（polyimide）纳米纤维与离子晶体构成。得益于离子晶体在相变点处的电导率突变（变化幅度超过3个数量级），该自供电报警器在室温下可保持稳定的储能性能（维持1.3 V以上的高电势），并在火灾场景中展现出灵敏的温度响应特性。此外，依托离子晶体的结构可设计性，其相变点可根据需求进行调节（例如40 ℃、60 ℃与90 ℃）。因此，基于聚酰亚胺/离子晶体的自供电报警器可实现基于温度分级的多级火灾预警。这款自供电智能报警器的这些独特性能，可有效降低火灾带来的损失，守护人类生命安全。