Waxberry‐Shaped Ordered Mesoporous P‐TiO_2−x Microspheres as High‐Performance Cathodes for Lithium–Sulfur Batteries

Abstract

As a candidate for a new generation of inexpensive and high‐performance energy storage systems, lithium–sulfur (Li–S) batteries have attracted widespread research. However, the development and application of Li–S batteries are limited by severe polysulfide dissolution and slow reaction kinetics. Herein, a type of ordered mesoporous P‐TiO2−x microsphere with a waxberry‐like shape as the sulfur host material for Li–S batteries is put forward, which combines the radially arranged mesoporous structure with oxygen defects in the mesoporous framework. In addition, the introduction of phosphorus impurities greatly improves the conductivity of the sulfur electrode, enhances electron mobility, and promotes the interaction between the sulfur species and P‐TiO2−x microspheres. Finally, S/P‐TiO2−x cathodes have achieved a high capacity of 1174.9 mAh g−1 at 0.2C and stable cycling (the average capacity attenuation is only 0.086% per cycle at 1C after 600 cycles).

Rapid Preparation of Uniform High-Crystallized Mesoporous Titania Spheres without High-Temperature Treatment

“…Thus, the well-crystallized uniform mesoporous TiO 2 spheres can be prepared with a very short total reaction time of only 4 h without high-temperature treatment in a mixed water/ethanol solution. In contrast, various mesoporous TiO 2 materials with high crystallinity need a long preparation time and a high-temperature treatment (Table S1), ,,,,,,− including spheres, ,,,,− , crystals, hollow structures, ,, composites, sheets, ,, and nanoparticles. ,,, In addition, the HDA can be cycled and reused to prepare the mesoporous TiO 2 materials, which has been proved in our recent report . Thus, this work demonstrates that the uniform high-crystallized mesoporous TiO 2 spheres can be prepared using a rapid, effective, and low-cost strategy free of high-temperature treatment.…”

Rough Endoplasmic Reticulum Inspired Polystyrene‐Brush‐Based Superhigh Sulfur Content Cathodes Enable Lithium–Sulfur Cells with High Mass and Capacity Loading

“…[42] In particular, the peak at 164.5 eV is attributed to R-S-C, which confirms that part of sulfur atoms are involved in the formation of fused polybenzothiophene skeletons. [43] Solid 13 C NMR spectroscopy was employed to determine the basic chemical structure of G-g-sPS@S. Methylene carbons from PS side-chains disappear, and a broad peak at δ 115-150 ppm could be assigned to carbon nuclei in condensed aromatic compounds, which is in accordance with the structure of vulcanized PS (Figure S11, Supporting Information). [36,44] Furthermore, the vulcanization reaction between G-g-PS and S 8 was investigated by TGA coupled with mass spectroscopy(Figure S12, Supporting Information).…”

“…Lithium-sulfur (Li-S) cells, which involve a sequence of complicated electrochemical transformations between sulfur and lithium (S 8 ↔ Li 2 S 8 ↔ Li 2 S 6 ↔ Li 2 S 4 ↔ Li 2 S 2 ↔ Li 2 S), have aroused extensive attention in the next-generation energy storage systems due to the ultrahigh theoretical capacity (1675 mAh g −1 ), high natural abundance, and environmental friendliness. [11][12][13] However, they are seriously plagued by the shuttle effect of intermediate lithium polysulfides, low conductivity of sulfur and lithium sulfides, and large volume expansion during charge and discharge processes, [14] which impedes the translation of academic interest to commercial applications. In the past decade, numerous efforts have been made to address these issues for sulfur cathodes through physical confinement or chemical adsorption/catalysis.…”

Diagnosing and Correcting the Failure of the Solid‐State Polymer Electrolyte for Enhancing Solid‐State Lithium–Sulfur Batteries

“…In organic liquid electrolytes (LEs), soluble lithium polysulfides (LiPS) act as indispensable redox intermediates to supply reversible Li-S reactions. [5,6] These species, however, also result in undesirable LiPS shuttling to damage cell reversibility, passivate the Li anode, and induce self-discharge, which fundamentally limits the operation performance and practical deployment of Li-S batteries. [7] Replacing vulnerable LEs with robust yet nonleaky solidstate electrolytes offers the solution to high-performance and reliable Li-S batteries.…”