Lithiated Phosphoryl Cellulose Nanocrystals Enhance Cycling Stability and Safety of Quasi-Solid-State Lithium Metal Batteries

Cycling stability and safety are two of the main challenges facing lithium metal batteries with metallic lithium as anodes. Quasi-solid-state lithium metal batteries based on gel polymer electrolytes are one of the important development directions for lithium metal batteries addressing those challenges. Herein, we prepare lithiated phosphoryl cellulose nanocrystals (PCNC-Li) as a modification material for poly(vinylidene fluoride) (PVDF) gel polymer electrolyte to improve cycling stability and safety of quasi-solid-state lithium metal batteries. The synthesized PCNC-Li tends to form a uniform network structure on the surface of the PVDF membrane, in which the phosphoryl groups grafted regularly on celluloses can regulate the transport of lithium ions. As a result, a more uniform ion flux and more stable lithium anode interface support an obviously improved cycling stability for lithium metal batteries. Moreover, the introduction of the PCNC-Li coating layer makes the modified PVDF membranes have a better thermal stability and an enhanced mechanical strength, which is beneficial for improvement of safety of lithium metal batteries. This work provides a new alternative to fabricating a better composite gel polymer electrolyte for lithium metal batteries.

Automated summary

This study focuses on improving the cycling stability and safety of quasi-solid-state lithium metal batteries by synthesizing lithiated phosphoryl cellulose nanocrystals (PCNC-Li) and incorporating them into poly(vinylidene fluoride) (PVDF) gel polymer electrolyte. The PCNC-Li forms a uniform network structure on the surface of PVDF membranes, regulating the transport of lithium ions and enhancing the stability of the lithium anode interface. Additionally, the PCNC-Li coating layer improves the thermal stability and mechanical strength of PVDF membranes, thus enhancing the safety of lithium metal batteries. This work provides a new option for fabricating a better composite gel polymer electrolyte for lithium metal batteries.