Research on the Preparation of Supercapacitor Separators with High Wettability and Excellent Temperature Adaptability Through In Situ Deposition of Nano-Barium Sulfate on Regenerated Cellulose

In this paper, environmentally friendly separator materials with high mechanical and electrochemical properties were prepared from regenerated cellulose. This was achieved by studying the drawbacks of existing supercapacitor separators and then preparing protofibrillated fibers and nanofibrillated cellulose. The process involved the in situ deposition of nano-BaSO4 using paper milling and papermaking techniques. The separators were tested for a tensile strength of 47.25 MPa, puncture strength of 156 gf, and tear strength of 8.9 KPa-m2/g; uniform pore size (0.6–2 μm) and abundant porosity (81.3%); good wettability (9.2°) and water absorption; and excellent temperature resistance (no deformation at 180 °C), as well as good temperature adaptability from −40 °C to 100 °C. This simple process, suitable for mass production, enables the development of a new separator material with great application potential.