A Supertough, Nonflammable, Biomimetic Gel with Neuron‐Like Nanoskeleton for Puncture‐Tolerant Safe Lithium Metal Batteries

To overcome the critical safety and performance issues of lithium metal batteries, it is urgent to develop advanced electrolytes with multi‐defensive properties against fire, mechanical puncture, and dendrite growth simultaneously, in addition to high ion‐conductivity. However, realizing these essential properties by one electrolyte has proved to be extremely challenging due to the inherent conflicts among them. Herein, to circumvent this challenge, a neuron‐like gel polymer electrolyte (simply referred as Neu‐PE) to simultaneously achieve supertoughness, nonflammability, dendrite‐suppression capability and self‐driven property is reported. This Neu‐PE takes advantage of nano‐phase separation regulated by highly ion‐conductive deep‐eutectic solvent. As a result, the Neu‐PE holds high ambient ionic conductivity (1.27±0.09 mS cm−1), super‐toughness and strength (22.52 MJ m−3 and 13.5±0.6 MPa), fire resistance and importantly, lithium‐metal anode protection capability. Lithium metal batteries assembled with this multi‐defensive Neu‐PE can work normally even under metal‐probe puncture or serious damage by cutting. To circumvent the persistent challenges of lithium‐metal batteries, a supertough polymer electrolyte with multi‐defensive properties against mechanical puncture, dendrite growth and flame is fabricated. This electrolyte obtains multiscale biomimetic properties in its structure and composition distribution, ensuring the comprehensive attainment of excellent mechanical properties, high ambient ionic conductivity, flame resistance, and lithium metal protection.