This study prepares highly porous carbon (c-fPI) for lithium-ion battery anode that starts from the synthesis of fluorinated polyimide (fPI) via a step polymerization, followed by carbonization. During the carbonization of fPI, the decomposition of fPI releases gases which are particularly from fluorine-containing moiety (–CF3) of fPI, creating well-defined microporous structure with small graphitic regions and a high specific surface area of 934.35 m2 g− 1. In particular, the graphitic region of c-fPI enables lithiation–delithiation processes and the high surface area can accommodate charges at electrolyte/electrode interface during charge–discharge, both of which contribute electrochemical performances. As a result, c-fPI shows high specific capacity of 248 mAh g− 1 at 25 mA g− 1, good rate-retention performance, and considerable cycle stability for at least 300 charge–discharge cycles. The concept of using a polymeric precursor (fPI), capable of forming considerable pores during carbonization is suitable for the use in various applications, particularly in energy storage systems, advancing materials science and energy technologies.

Porous carbon anodes from fluorinated polyimide for lithium-ion batteries
    Abstract
    1 Introduction
    2 Materials and methods
        2.1 Synthesis of poly(amic acid) (PAA) and fluorinated polyimide (fPI)
        2.2 Preparation of LIB electrode
        2.3 Characterization
    3 Results and discussion
    4 Conclusion
    Acknowledgements 
    References

• Eun Seo Kim(School of Chemical Engineering, School of Semiconductor and Chemical Engineering, and Clean Energy Research Center, Jeonbuk National University, Jeonju 54896, Republic of Korea)
• Hyeongmin Park(School of Chemical Engineering, School of Semiconductor and Chemical Engineering, and Clean Energy Research Center, Jeonbuk National University, Jeonju 54896, Republic of Korea)
• Sung‑Kon Kim(School of Chemical Engineering, School of Semiconductor and Chemical Engineering, and Clean Energy Research Center, Jeonbuk National University, Jeonju 54896, Republic of Korea) Corresponding author