J. Mater. Sci. Technol. ›› 2022, Vol. 104: 88-97.DOI: 10.1016/j.jmst.2021.06.054

• Research Article • Previous Articles     Next Articles

Direct synthesis of tin spheres/nitrogen-doped porous carbon composite by self-formed template method for enhanced lithium storage

Kun Liua, Jia-ao Wangb, Hongfei Zhengc, Xiaodong Suna, Zhimo Yanga, Jianzong Mana, Xinyu Wanga, Juncai Suna,*()   

  1. aInstitute of Materials and Technology, Dalian Maritime University, Dalian 116026, China
    bDepartment of Chemistry and the Oden Institute for Computational Engineering and Sciences, The University of Texas at Austin, Austin, TX, 78712-0165, USA
    cCollege of Materials, Xiamen University, Xiamen 361005, China
  • Received:2021-04-22 Revised:2021-06-14 Accepted:2021-06-20 Published:2022-03-30 Online:2022-03-30
  • Contact: Juncai Sun
  • About author:* E-mail address: sunjc@dlmu.edu.cn (J. Sun).
    First author contact:

    1 These authors contributed equally to this work.

Abstract:

To inhibit the agglomeration of tin-based nanomaterials and simplify the complicated synthesis process, a facile and eco-friendly self-formed template method is reported to synthesize tin submicron spheres dispersed in nitrogen-doped porous carbon (Sn/NPC) by pyrolysis of a mixture of disodium stannous citrate and urea. The vital point of this strategy is the formation of Na2CO3 templates during pyrolysis. This self-formed Na2CO3 acts as porous templates to support the formation of NPC. The obtained NPC provides good electronic conductivity, ample defects, and more active sites. Serving as anode for Li-ion batteries, the Sn/NPC electrode obtains a stable discharge capacity of 674.1 mAh/g after 150 cycles at 0.1 A/g. Especially, a high discharge capacity of 331.2 mAh/g can be achieved after 1100 cycles at 3 A/g. Additionally, a full cell coupled with LiCoO2 as cathode yields a discharge capacity of 524.8 mAh/g after 150 cycles at 0.1 A/g. In-situ XRD is implemented to investigate the alloying/dealloying reaction mechanisms. Density functional theory calculation ulteriorly explicates that NPC heightens intrinsic electronic conductivity, and NPC especially pyrrolic-N and pyridinic-N doping facilitates the Li-adsorption ability. Climbing image nudged elastic band method reveals low Li+ diffusion energy barrier in presence of N atoms, which accounts for the terrific electrochemical properties of Sn/NPC electrode.

Key words: Tin submicron spheres, Nitrogen-doped porous carbon, Self-formed template, In-situ XRD, Li-ion batteries