Spray-coated nanocellulose based separator/electrode assembly

• A separator-electrode assembly (SEA) made of wood-based cellulose nanofibers (CNF) and Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) was fabricated by a facile spray-coating process. CNF building blocks were prepared by homogenizing enzymatically pretreated cellulose fibers dispersed in a non-hazardous solvent, 2-propanol (IPA). The porous composite separator was made by spray-coating thin layers CNF-IPA, followed by a PVDF-HFP spray coating, on a lithium ion battery electrode. A CNF substrate was crucial for making a highly porous and thermally stable separator and PVDF-HFP coating enhanced its mechanical stability. The SEA maintained dimensional integrity when subjected to high temperature and when used in lithium ion batteries. A CNF-LiNi1/3Co1/3Mn1/3O2 (NMC) SEA showed excellent electrochemical stability, especially at fast charging/discharging rate, whereas a graphite counterpart showed poor electrochemical performance, resulting in cell failure. A SiO2 layer overcoated on the top of CNF-NMC SEA enabled its application for a proof-of-concept lithium metal battery and for a high energy‐density LiNi0.6Co0.2Mn0.2O2 (NMC622) lithium‐ion battery with excellent electrochemical stability and performances. The utilization of biodegradable materials and non-hazardous solvents such as IPA and acetone makes the development of the CNF based SEA attractive, as an eco-friendly lithium ion battery manufacturing process.

Ämnesord

TEKNIK OCH TEKNOLOGIER  -- Kemiteknik (hsv//swe)

ENGINEERING AND TECHNOLOGY  -- Chemical Engineering (hsv//eng)

Nyckelord

Energy Technology

Energiteknik

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