Suppressed dendrite formation realized by selective Li deposition in all-solid-state lithium batteries

Abstract Solid polymer electrolytes (SPEs)-based all-solid-state lithium batteries (ASSLBs) with high-safety and high-performance have been regarded as promising next-generation energy storage devices. A fly in the ointment is that the cycling life is significantly limited by the Li dendrite growth. To tackle the Li dendrite issue, a selective Li deposition strategy is proposed, for the first time, to suppress Li dendrite formation via the rational design of a patterned Li anode. Through a facile and low-cost template-press method, the Li anode was divided into numerous square Li with deep grooves around 100 ​μm. Benefiting from the focused current density in the grooves, the Li preferentially deposits in the grooves instead of on the surface, thus suppressing the Li dendrite formation during the Li plating/stripping process. With this in mind, both cycling life of the assembled Li–Li symmetric cells and Li–LiFePO4 (LFP) full cells is prolonged for over 5 times. The Li–Li symmetric cells assembled with the patterned Li exhibit excellent cycling stability for 800/400 ​h ​at 0.1/0.2 ​mA ​cm−2. More importantly, the 3–4 ​mg ​cm−2 LFP-loaded patterned Li/PEO/LFP cell achieves high capacity retention of 91.3% within 100 cycles at 0.5C, while different degrees of short-circuits occurred for the bare Li/PEO/LFP cells.