Microwave-assisted synthesis of Cr3C2@C core shell structure anchored on hierarchical porous carbon foam for enhanced polysulfide adsorption in Li-S batteries

• Published in: Nano research 2021-07, Vol.14 (7), p.2345-2352
• Main Authors: Zeng, Xierong, Tu, Jianxin, Chen, Shuangshuang, Zeng, Shaozhong, Zhang, Qi, Zou, Jizhao, Li, Kezhi
• Format: Article
• Language: English
• Subjects: Adsorption; Atomic/Molecular Structure and Spectra; Biomedicine; Biotechnology; Carbon; Chemistry and Materials Science; Chromium; Chromium carbide; Condensed Matter Physics; Core-shell structure; Decay rate; Discharge; Electrodes; First principles; Lithium; Lithium sulfur batteries; Materials Science; Nanoparticles; Nanotechnology; Polysulfides; Research Article; Structural hierarchy; Substrates; Sulfur
• ISSN: 1998-0124; 1998-0000
• DOI: 10.1007/s12274-020-3233-7

In this paper, we use microwave reduction strategy to synthesize a new bi-functional sulfur host material at the service of cathode substrate for lithium-sulfur batteries (LSBs), the composite is made of hierarchical porous carbon foam supported carbon-encapsulated chromium carbide nano-particles (Cr 3 C 2 @C/HPCF), in which the well-distributed conductive Cr 3 C 2 nano-particles can act as powerful chemical adsorbent and are effective in restraining the shuttle effect of lithium polysulfides (LiPSs). Test results show that the Cr 3 C 2 @C/HPCF based sulfur electrodes with 75 wt.% of sulfur exhibit a high initial discharging capacity of 1,321.1 mAh·g −1 at 0.1 C (3.5 mg·cm −2 ), and a reversible capacity can still maintain stability at 1,002.1 mAh·g −1 after 150 cycles. Even increasing the areal sulfur loading to 4 mg·cm −2 , the electrodes can still deliver an initial discharging capacity of 948.0 mAh·g −1 at 0.5 C with ultra-slow capacity decay rate of 0.075% per cycle during 500 cycles. Furthermore, the adsorption energy between the Cr 3 C 2 surface and LiPSs as well as theoretic analysis based on first-principles is also investigated.