Preparation of nitrogen doped hyper-crosslinked polymer-based hard carbon for high performance Li+/Na+ battery anode

Hyper cross-linked polymers (HCPs), as a key precursor of hard carbon (HC) anode materials, stand out because of their capacity for molecular-scale structural design and comparatively straightforward preparation techniques, which are not seen in other porous materials synthesized procedure. A novel synthesis method of HCPs is developed in this paper, which is through the incorporation of functional macromolecules , the structural control and heteroatom doping of the product has been achieved, thus augmenting its electrochemical performance in batteries. In this work, carbonized tetraphenylporphyrin zinc (TPP-Zn) doped HCP-based hard carbon (CTHCP) with stable structure was prepared by Friedel-Crafts reaction and carbonization by using naphthalene and trace TPP-Zn as monomers, dimethoxybenzene (DMB) as crosslinking agent and FeCl 3 as catalyst. The introduction of TPP-Zn, a functional macromolecule with unique two-dimensional structure, realized the pore structure regulation and N doping of the raw carbonized HCP-based hard carbon (CHCP). The results showed that CTHCP had higher mesoporous volume, N content and wider layer spacing than CHCP. In addition, CTHCP anode exhibited excellent Li + /Na + storage performance, initial reversible capacity, rate performance and long cycle life. More amount of N -containing (N-5) active sites and mesoporous content in CTHCP anode was the main reason for the improvement of Na + storage effect. While the increased interlayer spacing had a greater effect on the lithium storage capacity. This study uncovered the design rules of HC anode materials suitable for Li + /Na + batteries and provided a new idea for the preparation of high-performance HC anode materials.