A carbon matrix for high-capacity Li/Na/K-alloy-based anode materials is required because it can effectively accommodate the variation in the volume of Li/Na/K-alloy-based anode materials during cycling. Herein, a nanostructured porous polyhedral carbon (PPC) was synthesized via a simple two-step method consisting of carbonization and selective acid etching, and their electrochemical Li/Na/K-ion storage performance was investigated. The highly uniform PPC, with an average particle size of 800 nm, possesses a porous structure and large specific surface area of 258.82 cm2 g– 1. As anodes for Li/Na/K-ion batteries (LIBs/NIBs/KIBs), the PPC matrix exhibited large initial reversible capacity, fast rate capability (LIB: ~ 320 mAh g– 1 at 3C; NIB: ~ 140 mAh g– 1 at 2C; KIB: ~ 110 mAh g– 1 at 2C), better cyclic performance (LIB: ~ 550 mAh g– 1; NIB: ~ 210 mAh g– 1; KIB: ~ 190 mAh g– 1 at 0.2C over 100 cycles), high ionic diffusivity, and excellent structural robustness upon cycling, which demonstrates that the PPC matrix can be highly used as a carbon matrix for high-capacity alloy-based anode materials for LIBs/NIBs/KIBs.

Porous polyhedral carbon matrix for high-performance LiNaK-ion battery anodes
    Abstract
        Graphical abstract
    1 Introduction
    2 Experimental
        2.1 Material synthesis
        2.2 Material characterization
        2.3 Electrochemical measurements
    3 Results and discussion
    4 Conclusions
    Acknowledgements 
    References

• Cheol‑Min Park(School of Materials Science and Engineering, Kumoh National Institute of Technology, Gumi, Gyeongbuk 39177, Republic of Korea, Department of Energy Engineering Convergence, Kumoh National Institute of Technology, Gumi, Gyeongbuk 39177, Republic of Korea)
• Heechul Jung(Department of Energy and Mineral Resources Engineering, Dong-A University, Saha‑gu, Busan 49315, Republic of Korea)
• Young‑Han Lee(School of Materials Science and Engineering, Kumoh National Institute of Technology, Gumi, Gyeongbuk 39177, Republic of Korea, Department of Energy Engineering Convergence, Kumoh National Institute of Technology, Gumi, Gyeongbuk 39177, Republic of Korea)
• Vinoth Ganesan(School of Materials Science and Engineering, Kumoh National Institute of Technology, Gumi, Gyeongbuk 39177, Republic of Korea)