In situ construction and characteristics play a crucial role in developing high-energy-density lithium metal batteries (LMBs). Achieving dense deposition at the bottom and mechanical stability at the top are key factors for the success of high-areal-capacity Li metal anodes. A composite protective layer comprising Y-doped Li metal and LiF-rich solid electrolyte interface (SEI) has been proposed to regulate Li metal’s crystallographic orientation and enhance mechanical stability.
Experimental results confirm that the YP composite layer successfully alters the preferred crystallographic orientation of Li metal, promoting growth along the (200) plane instead of the (110) plane. This orientation shift reduces side reactions between Li metal and electrolytes, inhibits dendrite growth, and accelerates charge transfer kinetics. Additionally, Y-doping into Li metal induces the formation of a stable and dense SEI, further improving the battery’s cycling performance.
Characterization techniques such as X-ray diffraction, Cryo-TEM, XPS, and FTIR spectroscopy provide valuable insights into the structural and compositional changes induced by the YP layer. The mechanical stability of the SEI and Li metal deposition morphology are significantly enhanced by the presence of YP, leading to improved battery performance and longevity.
Further tests on coin-type and pouch-type full cells validate the effectiveness of the YP layer in enhancing capacity retention, stability, and energy density of LMBs. The YP-Li anode coupled with NCM811 cathode exhibits superior cycling performance under practical conditions, surpassing the energy density of most reported Li metal pouch cells.
Overall, the synergetic regulation strategy of SEI mechanics and crystallographic orientation through the YP composite layer shows great promise for advancing the development of high-energy-density LMBs with enhanced cycling stability and efficiency.
