A Core@sheath Nanofibrous Separator for Lithium Ion Batteries Obtained by Coaxial Electrospinning

A composite core@sheath nanofibrous separator for lithium ion batteries is fabricated via coaxial electrospinning, using thermosetting PI as the core material and PVDF‐HFP as the sheath material. It is demonstrated that the PI@PVDF‐HFP nonwovens display remarkably improved tensile strength up to 53 MPa and high thermal stability up to 300 °C. The electrochemical characterization shows that cells using core@sheath nonwovens as separators display better rate capability and better cycling capacity retention. Considerable mechanical strength, higher thermal stability and preferable rate capability might make this kind of core@sheath nonwovens promising separators for higher‐power application. magnified image