Fabrication of oriented-macroporous-carbon incorporated with γ-Al2O3 for high performance lithium-sulfur battery

This research presents a new insight into MOFs-derived materials with oriented macropores and ultrahigh specific surface area. The oriented-macroporous-carbon (OMC) incorporated with gamma-Al2O3 is prepared through pyrolysis of a glucose-urea-resin-filled MOF MIL-53 with double templates of NaCl-KCl eutectic and nano-CaCO3. The glucose-urea resin and NaCl-KCl eutectic fill the tunnels in the MIL-53 to avoid tunnel collapse and combination during pyrolysis. The nano-CaCO3 stays out of the tunnels to prevent from forming sealed tunnels. The synthesized OMC exhibits excellent polysulfide absorption capability, ascribed to its ultrahigh specific surface area and the coexistence of active O and N sites for polysulfide absorption. The resultant sulfur electrode shows much high discharge capacity, long life, and excellent rate performance. An initial capacity of 1626 mAh g(-1) at 0.05 C and a rate capacity as high as 430 mAh g(-1) at 10 C are achieved. A reversible capacity of 850 mAh g(-1) is retained after 300 cycles at a discharge rate of 0.2 C.