Ultrathin, Mechanically Durable, and Scalable Polymer ‐in‐Salt Solid Electrolyte for High‐Rate Lithium Metal Batteries

Al2O3 coated polyethylene (PE/AO) separators are proposed to fabricate ultrathin, mechanically durable, and scalable polymer-in-salt (PIS) solid-state electrolytes. The Al2O3 coating significantly improves the wettability, mechanical durability, and thermal stability of PIS electrolytes. The resulting PE/AO@PIS thus exhibits favorable ionic transferability for high-rate solid-state lithium-metal-based symmetrical and full cells. AbstractPolymer-in-salt solid-state electrolytes (PIS SSEs) are emerging for high room-temperature ionic conductivity and facile handling, but suffer from poor mechanical durability and large thickness. Here, Al2O3-coated PE (PE/AO) separators are proposed as robust and large-scale substrates to trim the thickness of PIS SSEs without compromising mechanical durability. Various characterizations unravel that introducing Al2O3 coating on PE separators efficiently improves the wettability, thermal stability, and Li-dendrite resistance of PIS SSEs. The resulting PE/AO@PIS demonstrates ultra-small thickness (25  µm), exceptional mechanical durability (55.1 MPa), high decomposition temperature (330 °C), and favorable ionic conductivity (0.12 mS cm−1 at 25  °C). Consequently, the symmetrical Li cells remain stable at 0.1 mA cm−2 for 3000 h, without Li dendrite formation. Besides, the LiFePO4|Li full cells showcase excellent rate capability (131.0 mAh g−1 at 10C) and cyclability (93.6% capacity retention at 2C after 400 cycles), and high-mass-lo...
Source: Small - Category: Nanotechnology Authors: Tags: Research Article Source Type: research