Scale-Up Synthesis and Characterization of Epoxyphenolics Based Pyrolysis Carbons as Highly-Performed Anodes for Li-Ion Batteries

Аннотация

A scalable synthesis of unique pyrolysis carbons from phosphorus-doped epoxyphenolics (EPN) through a facile curing and pyrolysis process is reported. The obtained carbons with a high pyrolysis yield of ca. 48% are investigated by SEM, TEM, XRD, Raman and nitrogen adsorption, and evaluated as anode for LIBs. The results show that the nanocrystal structure, proportion of defect sites and porosity (nanovoids) of the obtained carbons are highly dependent on pyrolysis temperature, thus affecting their electrochemical properties. The EPN carbon pyrolyzed at 900°C (EPN900) delivers the largest reversible capacity of nearly 420 mA h g^–1 at 0.1 C, which is higher than the theoretical capacity of graphite, mainly resulting from lithium-ions insertion into the turbostratic nanosheets and absorption on defect sites. While the EPN carbon pyrolyzed at 2800°C (EPN2800) exhibits a balanced lithium storage performance with relatively large reversible capacity of 343 mA h g^–1, high initial coulombic efficiency (~86%), and superior cycling performance (299 mA h g^–1 after 100 cycles at 0.3 C). This work provides a feasible solution for the large-scale preparation of high performance anode material and deepens the high-value utilization of the staple epoxy product.