3D flame-retardant skeleton reinforced polymer electrolyte for solid-state dendrite-free lithium metal batteries

For solid polymer electrolytes (SPEs), improving their mechanical and electrochemical properties is the key to obtaining batteries with higher safety and higher energy density. Herein, a novel synergistic strategy proposed is preparing a 3D flame-retardant skeleton (3DPA) and adding nano-multifunctional fillers ([email protected]). In addition to providing mechanical support for the polyethylene oxide (PEO) matrix, 3DPA also has further contributed to the system's flame retardancy and further improved the safety. Simultaneously, the electrochemical performance is fully guaranteed by rigid [email protected], which provides fast migration channels for Li+, reduces the crystallinity of PEO and effectively inhibits lithium dendrites. The limiting oxygen index of the optimal sample (PL3Z/PA) is as high as 20.5%, and the ionic conductivity reaches 2.89 × 10−4 and 0.91 × 10−3 S cm−1 at 25 and 55 °C, respectively. The assembled Li|PL3Z/PA|Li battery can be cycled stably for more than 1000 h at a current density of 0.1 mA cm−2 without short circuit being pierced by lithium dendrites. The specific capacity of the LFP|PL3Z/PA|Li battery was 160.5 mAh g−1 under a current density of 0.5 C, and the capacity retention rate was 90.0% after 300 cycles.