An <i>in Situ</i> Prepared Covalent Sulfur–Carbon Composite Electrode for High-Performance Room-Temperature Sodium–Sulfur Batteries

Self Cite

146

development of anode materials because graphite as the most successful commercial anode for LIBs has a poor Nastorage performance due to the mismatch between the large ion radius of Na + and the relatively narrow interlayer distance (<0.37 nm). [7][8][9] Hard carbon, composed of rich graphitic microcrystallites, pores, and defects, has been considered as a potential anode candidate for commercialization because it can deliver a considerable capacity of ≈300 mAh g -1 with a low discharge voltage and has abundant resources and low cost. [10][11][12][13] However, hard carbon still suffers from challenges of poor rate capability and cyclability. Great efforts have been made to overcome these obstacles. One strategy is to optimize precursors and reaction conditions. Based on this, a series of hard carbons derived from cellulose, [14] sugar, [15] polymers, [16,17] and biomass-based materials [18][19][20] have been reported with long cycle performance but limited storage capacity (<350 mAh g −1 ). Another strategy is to tune intrinsic carbon structures by heteroatom doping, such as boron, nitrogen, phosphorus, and sulfur. [21] Among them, N doping and S doping are the most widely investigated, since they can promote the adsorption of Na + and introduce abundant active sites for sodium storage, leading to an enhanced capacity. But they also bring an issue of relative high discharge voltage related to the high average oxidation voltage of N-related functional groups or reactive S dopant. [22][23][24][25][26] Compared with N and S doping, P doping can exhibit a stronger adsorption ability and display a great superiority of low discharge voltage (<1.0 V). [27][28][29][30][31][32][33] Unfortunately, the doping content of P is relatively low (<10 wt%), resulting in insufficient active sites for limited Na-storage capacity of hard carbon (<400 mAh g −1 ). The low doping levels can be attributed to following aspects: 1) The high binding energy and long bond length of PC (compared with CC) lead to severe lattice distortion when P is incorporated into the carbon skeleton, thus requiring a higher reaction energy. 2) The doped phosphorus is mostly in the form of PO x rather than elemental phosphorus. The electron-donating properties of P make it oxygen-sensitive and easy to oxidize to PO x groups, which can only be suspended outside the carbon plane, further hindering more P doping. 3) Most of the synthesis systems reported currently are unable to construct an oxygen-free Phosphorus doped carbons are of particular interest as anode materials because of their large interlayer spacing and strong adsorption of Na + ions. However, it remains challenging to achieve high phosphorus doping due to the limited choices of phosphorus sources and the difficulty in constructing oxygen-free synthesis system. Herein, a new synthesis strategy is proposed to prepare ultrahigh phosphorus-doped carbon (UPC) anodes for high performance sodium ion batteries (SIBs). By using two commonly available, miscible, evaporable liquids in PCl 3 and C 6 H 12 , ...

Section: Resultsmentioning

confidence: 99%

Ultrahigh Phosphorus Doping of Carbon for High‐Rate Sodium Ion Batteries Anode

Yan

Wang

et al. 2021

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146

“…c) Solvothermal synthesis of a covalent sulfur−carbon composite from carbon disulfide precursor in the presence of red phosphorus, and d) galvanostatic charge/discharge curves demonstrating the effect of prior electrochemical activation at low voltages of 0.01 to 3 V. Reproduced with permission. [ 200 ] Copyright 2020, American Chemical Society.…”

Section: Engineering Sulfur‐based Cathode Architectonicsmentioning

confidence: 99%

“…Another example of the “bottom‐up” synthetic approach employed an unconventional but interesting combination of carbon disulfide (CS 2 ) and red phosphorus, prepared in situ by a high pressure solvothermal method, exploiting the strong interaction between the two materials (Figure 20c). [ 200 ] The use of CS 2 as S‐precursor is fairly unusual due to its high volatility (boiling point: 46 °C) and also its associated toxicity. In this case however, the solvothermal vessel allowed for the high pressure and temperature necessary for CS 2 to exist as a supercritical fluid.…”

Section: Engineering Sulfur‐based Cathode Architectonicsmentioning

confidence: 99%

Room‐Temperature Sodium–Sulfur Batteries and Beyond: Realizing Practical High Energy Systems through Anode, Cathode, and Electrolyte Engineering

Eng

Kumar

Zhang

et al. 2021

134

The increasing energy demands of society today have led to the pursuit of alternative energy storage systems that can fulfil rigorous requirements like cost‐effectiveness and high storage capacities. Based fundamentally on earth‐abundant sodium and sulfur, room‐temperature sodium–sulfur batteries are a promising solution in applications where existing lithium‐ion technology remains less economically viable, particularly in large‐scale stationary systems such as grid‐level storage. Here, the key challenges in the field are first highlighted, followed by comprehensive analyses of accessible strategies to overcome them, starting from engineering of the anode–electrolyte interface in both liquid and solid electrolytes. Recently reported polymer and solid‐state electrolytes are also surveyed. Thereafter, the core principles guiding use‐inspired design of cathode architectures, covering the spectrum of elemental sulfur and polysulfide cathodes, to emerging host structures, and covalent composites are focused upon. Future prospects are explored, with insights into other alkali‐metal systems beyond sodium–sulfur batteries, such as the potassium–sulfur battery. Finally a conclusion is provided by outlining the research directions necessary to attain high energy sodium–sulfur devices, and potential solutions to issues concerning large‐scale production, so as to ultimately realize widespread deployment of practical energy storage systems.

“…In addition, Jiang et al applied an in situ wet-chemical solvothermal method to construct carbon nanostructures to enhance the adsorption of sulfur molecules. [85] The as-fabricated sulfur cathode presented extremely high specific capacities of 889 and 811 mAh g −1 after 600 cycles and 950 cycles at 0.8 and 1.6 C, respectively, and exceptional rate performance (700 mAh g −1 at 8.1 C), demonstrating great potential for practical RT Na-S batteries.…”

Section: Carbon/sulfur and Other Sulfur Composite Cathodesmentioning

confidence: 92%

“…In addition to the commercial porous carbon materials, [73,74] other porous carbon matrices prepared through the template method, [75][76][77][78][79] direct carbonization of biomass and organic complexes, [80][81][82][83][84] and wet-chemical synthesis approaches [85] have also been employed as sulfur hosts for RT Na-S batteries. Chou et al constructed an elaborately designed carbon framework, called interconnected mesoporous hollow carbon nanosphere, as a sulfur host for RT Na-S batteries (Figure 6a).…”

Section: Carbon/sulfur and Other Sulfur Composite Cathodesmentioning

confidence: 99%

Recent Advances in Emerging Non‐Lithium Metal–Sulfur Batteries: A Review

et al. 2021