Spontaneously Formed Mott‐Schottky Electrocatalyst for Lithium‐Sulfur Batteries

Abstract

are incontestable as a leading contender for next-generation energy storage system due to abundant sulfur source and high theoretical specific capacity. [2] However, some disadvantageous problems, such as sluggish multi-electron/ion conversion process, electron-insulating S or Li 2 S, and the shuttle effect of lithium polysulfide (LiPS), severely limit the energy efficiency and output power of Li-S batteries. [3] To achieve satisfactory electrochemical performance, numerous tactics have been proposed, including using special electrolyte or designing catalyst that catalyzes the conversion of LiPS. [4] The catalytic hosts are of particular interests owing to the advantages of lower reaction barriers, shortening the existence time of LiPS, thereby highly enhancing the utilization of sulfur species. [5] Given this, it is of great significance to develop highly reactivity and stability electrocatalysts for advanced Li-S batteries to realize high-efficient sulfurchemistry conversion.

Tubular CoFeP@CN as a Mott–Schottky Catalyst with Multiple Adsorption Sites for Robust Lithium−Sulfur Batteries

“…[25][26][27] This electric field with altered electron cloud density potentially promotes catalytic activity, suppress the shuttle effect, and boost lithium ion diffusion, subsequently improved Li-S performance. [28,29] Despite the great promise on regulating Li-S reaction, there is little research on Mott-Schottky catalyst up to date. And to the best of our knowledge, there is no report investigating the electronic structure of TMP/C 3 N 4 heterojunction attempt to apply for LSBs.…”

Manipulating Redox Kinetics of Sulfur Species Using Mott–Schottky Electrocatalysts for Advanced Lithium–Sulfur Batteries

“…17 These heterogeneous reactions intrinsically depend on the catalyst's surface electronic states. For most inorganic materials (such as N-doped C, 18 CoP, 15,19 TiO 2 , 20 MoS 2 , 21 and C 3 N 4 22,23 ), although they can immobilize polysulfides through a chemisorption mechanism, their semiconducting nature jeopardizes the electron transport to the surface-bonded polysulfide and the subsequent redox reactions of sulfur species (Figure 1a). 24 To this end, coupling these semiconductors with metallic phases as Mott−Schottky heterojunctions could be a proof-of-concept method to boost the catalytic activity by optimizing interfacial electronic interactions (Figure 1b).…”

In Situ Electrochemical Intercalation‐Induced Phase Transition to Enhance Catalytic Performance for Lithium–Sulfur Battery

“…Moreover, the TiN/1T-MoS 2 /S electrodes have a low polarization with a small voltage gap of 0.15 V, which is much less than that of both TiN/2H-MoS 2 /S (0.18 V) and TiO 2 /2H-MoS 2 /S (0.31 V) (Figure S12, Supporting Information). [27,58] The TiN/1T-MoS 2 /S cathodes also exhibit the favorable second discharge plateau around 2.1 V (the formation of short-chain LiPSs), suggesting the efficient utilization of the active sulfur materials. At this point, the TiN/1T-MoS 2 cathode in the absence of sulfur with a discharge capacity of 30 mAh g −1 under the same condition can be recognized to be negligible during the energy storage process (Figure S13, Supporting Information).…”

“…[24,25] Inspired by this, constructing heterojunctioncomposited cathode by combining different transition metal compounds for lithium-sulfur batteries is supposed to be an effective approach, aiming at integrating these properties together to achieve the facile trapping-diffusion conversion of LiPSs during the charge-discharge process. [26][27][28] Currently, the highly conductive titanium nitride (TiN) with outstanding chemical adsorption ability by polar interactions and molybdenum sulfide (MoS 2 ), especially for 1T-MoS 2 , with good catalytic effect toward LiPS reduction and Li 2 S oxidation have been widely applied into the fields of catalyst and energy storage. [29][30][31][32] There is no doubt that constructing heterojunction architecture of TiN/1T-MoS 2 can facilely integrate these favorable features of both TiN and 1T-MoS 2 , and the heterostructures are of particular importance due to the high electrical conductivity, good catalytic activity, as well as strong adsorption ability toward LiPSs, which can promote the electron transfer as well as accelerate the conversion rate during the charge-discharge process.…”