Confining Sulfur in N-Doped Porous Carbon Microspheres Derived from Microalgaes for Advanced Lithium–Sulfur Batteries

Abstract

Lithium-sulfur (Li-S) battery is one of the most attractive candidates for the next-generation energy storage system. However, the intrinsic insulating nature of sulfur and the notorious polysulfide shuttle are the major obstacles, which hinder the commercial application of Li-S battery. Confining sulfur into conductive porous carbon matrices with designed polarized surfaces is regarded as a promising and effective strategy to overcome above issues. Herein, we propose to use microalgaes (Schizochytrium sp.) as low-cost, renewable carbon/nitrogen precursors and biological templates to synthesize N-doped porous carbon microspheres (NPCMs). These rational designed NPCMs can not only render the sulfur-loaded NPCMs (NPCSMs) composites with high electronic conductivity and sulfur content, but also greatly suppress the diffusion of polysulfides by strongly physical and chemical adsorptions. As a result, NPCSMs cathode demonstrates a superior reversible capacity (1030.7 mA h g) and remarkable capacity retention (91%) at 0.1 A g after 100 cycles. Even at an extremely high current density of 5 A g, NPCSMs still can deliver a satisfactory discharge capacity of 692.3 mAh g. This work reveals a sustainable and effective biosynthetic strategy to fabricate N-doped porous carbon matrices for high performance sulfur cathode in Li-S battery, as well as offers a fascinating possibility to rationally design and synthesize novel carbon-based composites.

Sulfur Microspheres Encapsulated in Porous Silver‐Based Shell with Superior Performance for Lithium‐Sulfur Batteries

“…At the rate of 0.1 C, the electrode prepared with the S@Ag microsphere exhibits an initial discharge capacity as large as 1231 mAh g −1 , reaching 73.5 % of the theoretical capacity (Figure b), a performance over those of the pure S (with 1157 mAh g −1 at 0.1 C) or the S‐carbon composites reported recently . After 100 cycles, the electrode still demonstrated a value of 922 mAh g −1 , accounting for a decay of only 0.13 % per cycle and a capacity retention of 75 % (Figure c), which is much better than that given by the pure S electrode (which gave a capacity of 654 mAh g −1 after 100 cycles).…”

Silkworm Excrement Derived In‐situ Co‐doped Nanoporous Carbon as Confining Sulfur Host for Lithium Sulfur Batteries

“…The ICPC and ICPC−S composite were firstly characterized by XRD to identify their crystalline structures (Figure a) .The ICPC X‐ray diffraction pattern has only two broad peaks, it conforms to the typical characteristics of amorphous carbon,implying the largely amorphous nature of ICPC ,. On the contrary, ICPC−S displays typical sharp peaks, which demonstrates that the sulfur has entered the pores of the ICPC.…”

Multifunctionality of Carbon-based Frameworks in Lithium Sulfur Batteries

“…Conventional porous carbon materials can absorb polysulfide intermediates through physical interactions; however, the affinity between non-polar carbon hosts and polar lithium polysulfides is weak [115][116][117][118]. Therefore, carbon surfaces must be polarized to generate stronger chemical interactions between modified carbon matrixes and polysulfides.…”

“…Here, doping heteroatoms into carbon materials is a good approach to achieve this functionality on matrix surfaces. As an example, Xia et al [115] prepared N-doped porous carbon microspheres (NPCMs) using the heat treatment of microalgae (Fig. 8).…”

“…Hao [115] et al [127] further applied MOFs to prepare MOF-derived 2D nanocarbon materials using thermal exfoliation to synthesize effective Li-S battery cathodes. In their study, the researchers selected copper 4,4′-bipyridine MOFs (Fig.…”