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Li et al. Chem Synth 2023;3:30 https://dx.doi.org/10.20517/cs.2023.16 Page 13 of 17

Figure 5. Schematic mechanism of the MOF-derived hierarchically porous carbon for selenium confinement and the synergistic effect of
micropores and mesopores during the electrochemical reaction.

mesopores can achieve more efficient suppression of polyselenides dissolution and fast electrolyte
transportation at the same time.

CONCLUSIONS
Hierarchically micro-mesoporous carbon materials have been synthesized to confine Se by facile
carbonization of three kinds of aluminum-based MOFs. The hierarchically micro-mesoporous carbon
structure can confine Se well and alleviate the volume expansion, especially enhancing the adsorption of
soluble polyselenides, leading to improved battery performance. Especially, the micropores can efficiently
decrease the polyselenides dissolution to inhibit the shuttle effect, and the mesopores interconnected with
micropores can lead to good electrolyte transportation. These synergistic hierarchically micro-mesoporous
characteristics with a well-balanced ratio of micropores and mesopores achieved a capacity of 456.6 mA h
-1
-1
g for Se@MIL-53-800 and 530.1 mA h g for Se@MIL-68-800, compared to 348.4 mA h g for their fewer
-1
-1
mesopore counterparts Se@MIL-100-800 and 199.3 mA h g for pure Se cathode after 200 cycles. The
Se@MIL-68-800 also showed very good rate performance around 307 mA h g at 5 C and a high reversible
-1
-1
capacity of 544 mA h g when back to 0.1 C. Furthermore, the electrochemical performance of the battery
should be further improved through the modification of electrolytes to better match the prepared Se
cathode [83-85] . Our strategy not only provides a facile way to obtain hierarchically porous carbon from MOFs
but also gives insights on how to regulate the proportion of micropores and mesopores to achieve a better
Li-Se or Li-S battery performance.

DECLARATIONS
Acknowledgments
Hongyan Li and Chao Li thank the financial support from the China Scholarship Council (CSC) and a
scholarship from the Laboratory of Inorganic Materials Chemistry, Université de Namur. The authors thank
the help of battery impedance analysis from Prof. Alexandru Vlad (Institute of Condensed Matter and
Nanosciences, Université catholique de Louvain) and the support of bis(trifluoromethane)sulfonimide Li
salt from Solvey company. The authors thank the help of TEM characterization from Mr. Weichun Huang
(Shenzhen Engineering Laboratory of Phosphorene and Optoelectronics, Shenzhen University).

Authors’ contributions
Provided financial support: Su BL, Li Y
Revised and finalized the manuscript: Su BL, Li Y