Synthesis, Characterization, and Lib Cell Performance of Chemically-Derived Pure Crystalline Fullerene C60
Authors: Cho chae-Ryong , Yin Linghong , Chen Hong , Kang Min-Seung 
Published: December 2024

Buckminsterfullerene (C60), as an allotrope of carbon, is regarded as a potential anode material for lithium-ion batteries(LIBs). However, the poor crystallinity, low electrochemical reaction activity, and poor reversibility of lithium storage of C60 make it challenging to design efficient anode materials, and the relevant electrochemical reaction mechanisms still require in-depth study. Currently, many researches have been devoted to polymerized C60 and further modification through doping, hybridization, and derivatization to obtain high-performance C60-based anode materials. However, application of high crystallinity C60 nanomaterials in the anode materials of LIBs is rarely reported. Nanocarbon materials have high specific surface area, which can provide more lithium storage sites for lithium ions, shorten the transmission path of lithium ions, and make the diffusion and deintercalation of lithium ions in electrode materials faster. At the same time, nanocarbon materials have excellent conductivity which can increase the electron transfer rate in carbon materials, thereby improving the charge -discharge performance and cycle stability of the battery. Therefore, the development of C60 nanomaterials with high crystallinity and regular morphology as anode materials is extremely attractive and profound.

In this work, one-dimensional C60 nanorods(C60 NRs) with regular shape and high crystallinity were prepared through liquid-liquid interface precipitation(LLIP) method and low-temperature annealing process, to be served as anode material of LIBs. 1 M LiPF6 solution in ethylene carbonate (EC)/diethyl carbonate (DEC) (1:1 vol%) with 10% ﬂuoroethylene carbonate (FEC) was used as electrolyte. Electrochemical performance tests show that C60 NRs is a high-rate performance and long-cycle life anode material for LIBs. Maintaining a discharge-specific capacity of 603 mAh g−1 after 2,000 cycles at a current density of 2 A g−1. Even at a high current density of 10 A g−1, C60 NRs could still achieve a discharge-specific capacity of 228 mAh g−1 after 5,000 cycles. The chemical changes of the electrode surface components and the SEI layer formation mechanism during the electrochemical reaction were explored through XPS experiments. The results confirmed the reversible storage of lithium ions and the existence of inorganic components such as LiF, Li2CO3, Li2O and oligomer based organic materials in SEI film. All account for the excellent charge-discharge performance and cycle stability of C60 NRs anode. Furthermore, Galvanostatic intermittent titration technique(GITT) and potentiostat intermittent titration technique(PITT) tests were conducted to calculate diffusion coefficient of lithium ion during charge-discharge process, the obtained high diffusion coefficient demonstrated fast lithium diffusion and stable cycle performance of C60 NRs anode. This work proved the feasibility of C60 nanomaterials as high-performance energy storage anode materials and will help to promote the design of new C60-based nanomaterials for LIBs.

This research was supported by the NRF funded by the MSIT and MEST (grant numbers NRF-2021R1A4A1022198, NRF-2022R1A2B5B01001943, and NRF-2018R1A5A1025594).

Figure 1