Layered Polymer Stacking for Stable Interfaces and Dendrite Growth Inhibition in All-Solid-State Lithium Batteries

作者：Hu, Long; Gao, Xue; Li, Ziyong; Liu, Yuxuan^*; Wang, Hui; Liu, Jun; Hu, Renzong^*

来源：ACS applied materials & interfaces, 2023, 15(32): 38485-38495.

DOI：10.1021/acsami.3c07794

• poly(ethylene oxide)
• sandwich structure
• LiYF4
• TiN
• solid electrolyte

To improve the ionic conductivity and cycling stabilityof solid-statelithium batteries based on poly(ethylene oxide) (PEO) electrolytes,we developed a sandwich-structured composite polymer electrolyte (sandwich-CPE)PEO-TiN/PEO-LiYF4/PEO-TiN. The sandwich-CPE delivers ahigh ionic conductivity of 1.7 x 10(-4) S cm(-1) at 30 & DEG;C and a wide potential window of 0 to5.0 V (vs Li/Li+). Adding PEO-TiN leads to the formationof Li3N between Li and sandwich-CPE during cycling, whicheffectively reduces the level of Li dendrite formation. Additionally,PEO-TiN acts as a sacrificial layer to stop the entry of Li dendritesinto the interlayer PEO-LiYF4. Using the sandwich-CPE,LiFePO4 retains a reversible capacity of 113.8 mA h g(-1) at 30 & DEG;C after 300 cycles under 0.5 C. For high-voltagecells, LiNi0.5Co0.2Mn0.3O2 retains a capacity retention of 71.4% at 45 & DEG;C after 300 cyclesunder 0.2 C among 3.0-4.3 V, while Li3V2(PO4)(3) delivers an initial discharge capacityof 108.1 mA h g(-1) at 60 & DEG;C and retains 81.6%after 500 cycles under 1 C among 2.8-4.4 V. These results demonstratethe strong electrochemical compatibility of the sandwich-CPE, enablinghigh reversible capacity and good cycling stability for solid-stateLi batteries with different cathodes at different temperatures andcurrent rates.