锂硫电池复合正极研究进展

doi:10.13208/j.electrochem.2219013

摘要/Abstract

摘要：

锂硫电池因其超高的理论能量密度被视为极具前景的下一代电化学储能体系，其中高比容量的硫正极提供了锂硫电池的能量密度优势并直接决定了电池的实际性能。经过数十年的发展，最具前景的硫正极体系分别是硫碳复合（S/C）正极和硫化聚丙烯腈（SPAN）正极。本文系统综述了S/C正极和SPAN正极的最新研究进展。首先，简要介绍了两种正极的工作原理并进行了比较。S/C正极发生固-液-固多相转化反应，充放电表现为双平台特征。与之相比，SPAN正极发生固-固反应，充放电曲线为单平台。然后，对两种正极所面临的挑战和目前报道的优化策略进行了系统的分析与讨论。对于S/C正极，主要调控策略包括电极结构修饰、电催化剂设计与辅助氧化还原介体调控；对于SPAN正极，主要调控策略包括电极结构设计、电极形貌调控、杂原子掺杂和外源性氧化还原介体调控。最后，在电池尺度上对S/C正极和SPAN正极进行了综合比较，并对基于S/C正极和SPAN正极的锂硫电池在未来所面对的机遇与挑战进行了展望。

关键词: 锂硫电池, 硫碳复合正极, 硫化聚丙烯腈正极, 多硫化锂

Abstract:

Lithium-sulfur (Li-S) batteries are deemed as high-promising next-generation energy storage technique due to their ultrahigh theoretical energy density, where the sulfur cathodes with high specific capacity guarantee the energy density advantage and directly determine the battery performances. After decades of exploration, the most promising sulfur cathodes are sulfur/carbon composite (S/C) cathodes and sulfurized polyacrylonitrile (SPAN) cathodes. In this manuscript, recent advances on S/C and SPAN cathodes in Li-S batteries are comprehensively reviewed. The electrochemical reaction circumstances on S/C and SPAN cathodes are firstly introduced and compared to reveal the working mechanisms of the two types of Li-S batteries. The S/C cathodes mainly undergo solid-liquid-solid multi-phase conversion processes with typical double-plateau charge-discharge polarization curves. In comparison, the SPAN cathodes follow solid-solid conversion and exhibit single-plateau charge-discharge characteristics. Following that, key challenges and targeted optimizing strategies of the S/C and SPAN cathodes are respectively presented and discussed. For Li-S batteries with S/C cathodes, the main optimizing strategies are electrode structure modification, efficient electrocatalyst design, and redox comediation. For SPAN cathodes, the main optimizing strategies are electrode structure modification, morphology regulation by co-polymerization, heteroatom doping at molecular level, and extrinsic redox mediation. At last, current research status of Li-S batteries with S/C or SPAN cathodes are systematically analyzed through the comparison of several battery parameters, and perspectives on challenges and opportunities of S/C and SPAN cathodes in Li-S batteries are presented to guide future researches.

Key words: lithium-sulfur battery, sulfur/carbon composite cathode, sulfurized polyacrylonitrile cathode, lithium polysulfide

李西尧, 赵长欣, 李博权, 黄佳琦, 张强. 锂硫电池复合正极研究进展[J]. 电化学（中英文）, 2022, 28(12): 2219013.

Xi-Yao Li, Chang-Xin Zhao, Bo-Quan Li, Jia-Qi Huang, Qiang Zhang. Advances on Composite Cathodes for Lithium-Sulfur Batteries[J]. Journal of Electrochemistry, 2022, 28(12): 2219013.

图/表 6

参考文献 71

[1]	Shen L, Song Y W, Wang J, Zhao C X, Bi C X, Sun S Y, Zhang X Q, Li B Q, Zhang Q. Synergistic catalysis on dual-atom sites for high-performance lithium-sulfur batteries[J]. Small Struct., 2022: 2200205.
[2]	Wang Y, Lv Y, Su Y B, Chen L Q, Li H, Wu F. 5V-class sulfurized spinel cathode stable in sulfide all-solid-state batteries[J]. Nano Energy, 2021, 90: 106589. doi: 10.1016/j.nanoen.2021.106589 URL
[3]	Wu F, Liu L L, Wang S, Xu J R, Lu P S, Yan W L, Peng J, Wu D X, Li H. Solid state ionics -selected topics and new directions[J]. Prog. Mater. Sci., 2022, 126: 100921. doi: 10.1016/j.pmatsci.2022.100921 URL
[4]	Yao N, Chen X, Fu Z H, Zhang Q. Applying classical, ab initio, and machine-learning molecular dynamics simulations to the liquid electrolyte for rechargeable batteries[J]. Chem. Rev., 2022, 122(12): 10970-11021. doi: 10.1021/acs.chemrev.1c00904 URL
[5]	Wang Y, Wang Z X, Wu D X, Niu Q H, Lu P S, Ma T H, Su Y B, Chen L Q, Li H, Wu F. Stable Ni-rich layered oxide cathode for sulfide-based all-solid-state lithium battery[J]. eScience, 2022, 2(5): 537-545. doi: 10.1016/j.esci.2022.06.001 URL
[6]	Ye G, Zhao M, Hou L P, Chen W J, Zhang X Q, Li B Q, Huang J Q. Evaluation on a 400 Wh·kg^-1 lithium-sulfur pouch cell[J]. J. Energy Chem., 2022, 66: 24-29. doi: 10.1016/j.jechem.2021.07.010 URL
[7]	Wang J C, Zhang Z Y, Han J F, Wang X F, Chen L Q, Li H, Wu F. Interfacial and cycle stability of sulfide all-solid-state batteries with Ni-rich layered oxide cathodes[J]. Nano Energy, 2022, 100: 107528. doi: 10.1016/j.nanoen.2022.107528 URL
[8]	Peng H J, Huang J Q, Zhang Q. A review of flexible lithium-sulfur and analogous alkali metal-chalcogen rechargeable batteries[J]. Chem. Soc. Rev., 2017, 46(17): 5237-5288. doi: 10.1039/C7CS00139H URL
[9]	Yao N P, Heredy L A, Saunders R C. Secondary lithium-sulfur battery[J]. J. Electrochem. Soc., 1970, 117: C247.
[10]	Xue L X, Li Y Y, Hu A J, Zhou M J, Chen W, Lei T Y, Yan Y C, Huang J W, Yang C T, Wang X F, Hu Y, Xiong J. In-situ/operando Raman techniques in lithium-sulfur batteries[J]. Small Struct., 2022, 3(3): 2100170. doi: 10.1002/sstr.202100170 URL
[11]	Hou L P, Yao L Y, Bi C X, Xie J, Li B Q, Huang J Q, Zhang X Q. High-valence sulfur-containing species in solid electrolyte interphase stabilizes lithium metal anodes in lithium-sulfur batteries[J]. J. Energy Chem., 2022, 68: 300-305. doi: 10.1016/j.jechem.2021.12.024 URL
[12]	Song Y W, Peng Y Q, Zhao M, Lu Y, Liu J N, Li B Q, Zhang Q. Understanding the impedance response of lithium polysulfide symmetric cells[J]. Small Sci., 2021, 1(11): 2100042. doi: 10.1002/smsc.202100042 URL
[13]	Cheng X B, Yan C, Huang J Q, Li P, Zhu L, Zhao L, Zhang Y, Zhu W, Yang S T, Zhang Q. The gap between long lifespan Li-S coin and pouch cells: The importance of lithium metal anode protection[J]. Energy Storage Mater., 2017, 6: 18-25.
[14]	Kong L, Jin Q, Zhang X T, Li B Q, Chen J X, Zhu W C, Huang J Q, Zhang Q. Towards full demonstration of high areal loading sulfur cathode in lithium-sulfur batteries[J]. J. Energy Chem., 2019, 39: 17-22. doi: 10.1016/j.jechem.2018.12.012 URL
[15]	Chen W J, Li B Q, Zhao C X, Zhao M, Yuan T Q, Sun R C, Huang J Q, Zhang Q. Electrolyte regulation towards stable lithium-metal anodes in lithium-sulfur batteries with sulfurized polyacrylonitrile cathodes[J]. Angew. Chem. Int. Ed., 2020, 59(27): 10732-10745. doi: 10.1002/anie.201912701 URL
[16]	Cheng Q, Chen Z X, Li X Y, Hou L P, Bi C X, Zhang X Q, Huang J Q, Li B Q. Constructing a 700 Wh·kg^-1-level rechargeable lithium-sulfur pouch cell[J]. J. Energy Chem., 2023, 76: 181-186. doi: 10.1016/j.jechem.2022.09.029 URL
[17]	Holoubek J, Liu H D, Wu Z H, Yin Y J, Xing X, Cai G R, Yu S C, Zhou H Y, Pascal T A, Chen Z, Liu P. Tailoring electrolyte solvation for Li metal batteries cycled at ultra-low temperature[J]. Nat. Energy, 2021, 6(3): 303-313. doi: 10.1038/s41560-021-00783-z URL
[18]	Zhao M, Peng Y Q, Li B Q, Zhang X Q, Huang J Q. Regulation of carbon distribution to construct high-sulfur-content cathode in lithium-sulfur batteries[J]. J. Energy Chem., 2021, 56: 203-208. doi: 10.1016/j.jechem.2020.07.054 URL
[19]	Wang J L, Yang J, Xie J Y, Xu N X, Li Y. Sulfur-carbon nano-composite as cathode for rechargeable lithium battery based on gel electrolyte[J]. Electrochem. Commun., 2002, 4(6): 499-502. doi: 10.1016/S1388-2481(02)00358-2 URL
[20]	Ji X, Lee K T, Nazar L F. A highly ordered nanostructured carbon-sulphur cathode for lithium-sulphur batteries[J]. Nat. Mater., 2009, 8(6): 500-506. doi: 10.1038/nmat2460 URL
[21]	Manthiram A, Fu Y, Chung S H, Zu C, Su Y S. Recharge-able lithium-sulfur batteries[J]. Chem. Rev., 2014, 114(23): 11751-11787. doi: 10.1021/cr500062v pmid: 25026475
[22]	Zak J J, Kim S S, Laskowski F A L, See K A. An exploration of sulfur redox in lithium battery cathodes[J]. J. Am. Chem. Soc., 2022, 144(23): 10119-10132. doi: 10.1021/jacs.2c02668 pmid: 35653701
[23]	Li G R, Wang S, Zhang Y N, Li M, Chen Z W, Lu J. Revisiting the role of polysulfides in lithium-sulfur batteries[J]. Adv. Mater., 2018, 30(22): 1705590. doi: 10.1002/adma.201705590 URL
[24]	Lei J, Liu T, Chen J J, Zheng M S, Zhang Q, Mao B W, Dong Q F. Exploring and understanding the roles of Li₂S_n and the strategies to beyond present Li-S batteries[J]. Chem, 2020, 6(10): 2533-2557. doi: 10.1016/j.chempr.2020.06.032 URL
[25]	Meini S, Elazari R, Rosenman A, Garsuch A, Aurbach D. The use of redox mediators for enhancing utilization of Li₂S cathodes for advanced Li-S battery systems[J]. J. Phys. Chem. Lett., 2014, 5(5): 915-918. doi: 10.1021/jz500222f pmid: 26274088
[26]	Wang J L, Yang J, Xie J Y, Xu N X. A novel conductive polymer-sulfur composite cathode material for rechargeable lithium batteries[J]. Adv. Mater., 2002, 14(13-14): 963-965. doi: 10.1002/1521-4095(20020705)14:13/14<963::AID-ADMA963>3.0.CO;2-P URL
[27]	Chen Z Y, Zhou J J, Guo Y S, Liang C D, Yang J, Wang J L, Nuli Y N. A compatible carbonate electrolyte with lithium anode for high performance lithium sulfur battery[J]. Electrochim. Acta, 2018, 282: 555-562. doi: 10.1016/j.electacta.2018.06.093 URL
[28]	Wang W X, Cao Z, Elia G A, Wu Y Q, Wahyudi W, Abou-Hamad E, Emwas A H, Cavallo L, Li L J, Ming J. Recognizing the mechanism of sulfurized polyacrylonitrile cathode materials for Li-S batteries and beyond in Al-S batteries[J]. ACS Energy Lett., 2018, 3(12): 2899-2907. doi: 10.1021/acsenergylett.8b01945 URL
[29]	Fanous J, Wegner M, Grimminger J, Andresen Ä, Buchmeiser M R. Structure-related electrochemistry of sulfur-poly(acrylonitrile) composite cathode materials for re-chargeable lithium batteries[J]. Chem. Mater., 2011, 23(22): 5024-5028. doi: 10.1021/cm202467u URL
[30]	Zhang S S. Understanding of sulfurized polyacrylonitrile for superior performance lithium/sulfur battery[J]. Energies, 2014, 7(7): 4588-4600. doi: 10.3390/en7074588 URL
[31]	Warneke S, Hintennach A, Buchmeiser M R. Communication—influence of carbonate-based electrolyte composition on cell performance of span-based lithium-sulfur batteries[J]. J. Electrochem. Soc., 2018, 165(10): A2093. doi: 10.1149/2.0361810jes URL
[32]	Yang H J, Naveed A, Li Q Y, Guo C, Chen J H, Lei J Y, Yang J, Nuli Y N, Wang J L. Lithium sulfur batteries with compatible electrolyte both for stable cathode and dendrite-free anode[J]. Energy Storage Mater., 2018, 15: 299-307.
[33]	Li Q Y, Yang H J, Xie L S, Yang J, Nuli Y N, Wang J L. Guar gum as a novel binder for sulfur composite cathodes in rechargeable lithium batteries[J]. Chem. Commun., 2016, 52(92): 13479-13482. doi: 10.1039/C6CC07250J URL
[34]	Wei S, Ma L, Hendrickson K E, Tu Z, Archer L A. Metal-sulfur battery cathodes based on PAN-sulfur composites[J]. J. Am. Chem. Soc., 2015, 137(37): 12143-12152. doi: 10.1021/jacs.5b08113 pmid: 26325146
[35]	Zhao M, Li B Q, Peng H J, Yuan H, Wei J Y, Huang J Q. Lithium-sulfur batteries under lean electrolyte conditions: Challenges and opportunities[J]. Angew. Chem. Int. Ed., 2020, 59(31): 12636-12652. doi: 10.1002/anie.201909339 pmid: 31490599
[36]	Peng H J, Huang J Q, Cheng X B, Zhang Q. Review on high-loading and high-energy lithium-sulfur batteries[J]. Adv. Energy Mater., 2017, 7(24): 1700260. doi: 10.1002/aenm.201700260 URL
[37]	Li X Y, Feng S, Zhao M, Zhao C X, Chen X, Li B Q, Huang J Q, Zhang Q. Surface gelation on disulfide electrocatalysts in lithium-sulfur batteries[J]. Angew. Chem. Int. Ed., 2022, 61(7): e202114671.
[38]	Wang Z K, Li Y, Ji H Q, Zhou J Q, Qian T, Yan C L. Unity of opposites between soluble and insoluble lithium polysulfides in lithium-sulfur batteries[J]. Adv. Mater., 2022, 34(47).
[39]	Feng S, Singh R K, Fu Y C, Li Z, Wang Y L, Bao J, Xu Z J, Li G S, Anderson C, Shi L L, Lin Y H, Khalifah P G, Wang W, Liu J, Xiao J, Lu D P. Low-tortuous and dense single-particle-layer electrode for high-energy lithium-sulfur batteries[J]. Energy Environ. Sci., 2022, 15(9): 3842-3853. doi: 10.1039/D2EE01442D URL
[40]	Zhao C X, Li X Y, Zhao M, Chen Z X, Song Y W, Chen W J, Liu J N, Wang B, Zhang X Q, Chen C M, Li B Q, Huang J Q, Zhang Q. Semi-immobilized molecular electrocatalysts for high-performance lithium-sulfur batteries[J]. J. Am. Chem. Soc., 2021, 143(47): 19865-19872. doi: 10.1021/jacs.1c09107 URL
[41]	Zhao M, Li B Q, Chen X, Xie J, Yuan H, Huang J Q. Redox comediation with organopolysulfides in working lithium-sulfur batteries[J]. Chem, 2020, 6(12): 3297-3311. doi: 10.1016/j.chempr.2020.09.015 URL
[42]	Zhao M Q, Peng H J, Tian G L, Zhang Q, Huang J Q, Cheng X B, Tang C, Wei F. Hierarchical vine-tree-like carbon nanotube architectures: In-situ CVD self-assembly and their use as robust scaffolds for lithium-sulfur batteries[J]. Adv. Mater., 2014, 26(41): 7051-7058. doi: 10.1002/adma.201402488 URL
[43]	Lv D, Zheng J, Li Q, Xie X, Ferrara S, Nie Z, Mehdi L B, Browning N D, Zhang J G, Graff G L, Liu J, Xiao J. High energy density lithium-sulfur batteries: Challenges of thick sulfur cathodes[J]. Adv. Energy Mater., 2015, 5(16): 1402290. doi: 10.1002/aenm.201402290 URL
[44]	Zhang S J, Zhang Y S, Shao G S, Zhang P. Bio-inspired construction of electrocatalyst decorated hierarchical porous carbon nanoreactors with enhanced mass transfer ability towards rapid polysulfide redox reactions[J]. Nano Res., 2021, 14(11): 3942-3951. doi: 10.1007/s12274-021-3319-x URL
[45]	Kang N, Lin Y X, Yang L, Lu D P, Xiao J, Qi Y, Cai M. Cathode porosity is a missing key parameter to optimize lithium-sulfur battery energy density[J]. Nat. Commun., 2019, 10: 4597. doi: 10.1038/s41467-019-12542-6 pmid: 31601812
[46]	Wang F, Zuo Z C, Li L, He F, Li Y L. Graphdiyne nanostructure for high-performance lithium-sulfur batteries[J]. Nano Energy, 2020, 68: 104307. doi: 10.1016/j.nanoen.2019.104307 URL
[47]	Li B Q, Zhang S Y, Kong L, Peng H J, Zhang Q. Porphyrin organic framework hollow spheres and their applications in lithium-sulfur batteries[J]. Adv. Mater., 2018, 30(23): 1707483. doi: 10.1002/adma.201707483 URL
[48]	Liu X, Huang J Q, Zhang Q, Mai L. Nanostructured metal oxides and sulfides for lithium-sulfur batteries[J]. Adv. Mater., 2017, 29(20): 1601759. doi: 10.1002/adma.201601759 URL
[49]	Geng C N, Hua W X, Wang D W, Ling G W, Zhang C, Yang Q H. Demystifying the catalysis in lithium-sulfur batteries: Characterization methods and techniques[J]. SusMat, 2021, 1(1): 51-65. doi: 10.1002/sus2.5 URL
[50]	Al Salem H, Babu G, V. Rao C, Arava L M R. Electrocatalytic polysulfide traps for controlling redox shuttle process of Li-S batteries[J]. J. Am. Chem. Soc., 2015, 137(36): 11542-11545. doi: 10.1021/jacs.5b04472 pmid: 26331670
[51]	Zhou T H, Lv W, Li J, Zhou G M, Zhao Y, Fan S X, Liu B L, Li B H, Kang F Y, Yang Q H. Twinborn TiO₂-tin heterostructures enabling smooth trapping-diffusion-conversion of polysulfides towards ultralong life lithium-sulfur batteries[J]. Energy Environ. Sci., 2017, 10(7): 1694-1703. doi: 10.1039/C7EE01430A URL
[52]	Wang R C, Luo C, Wang T S, Zhou G M, Deng Y Q, He Y B, Zhang Q F, Kang F Y, Lü W, Yang Q H. Bidirectional catalysts for liquid-solid redox conversion in lithium-sulfur batteries[J]. Adv. Mater., 2020, 32(32): 2000315. doi: 10.1002/adma.202000315 URL
[53]	Zhao M, Peng H J, Li B Q, Chen X, Xie J, Liu X, Zhang Q, Huang J Q. Electrochemical phase evolution of metal-based pre-catalysts for high-rate polysulfide conversion[J]. Angew. Chem. Int. Ed., 2020, 59(23): 9011-9017. doi: 10.1002/anie.202003136 pmid: 32203631
[54]	Xue W J, Shi Z, Suo L M, Wang C, Wang Z A, Wang H Z, So K P, Maurano A, Yu D W, Chen Y M, Qie L, Zhu Z, Xu G Y, Kong J, Li J. Intercalation-conversion hybrid cathodes enabling Li-S full-cell architectures with jointly superior gravimetric and volumetric energy densities[J]. Nat. Energy, 2019, 4(5): 374-382. doi: 10.1038/s41560-019-0351-0 URL
[55]	Li X Y, Feng S, Zhao C X, Cheng Q, Chen Z X, Sun S Y, Chen X, Zhang X Q, Li B Q, Huang J Q, Zhang Q. Regulating lithium salt to inhibit surface gelation on an electrocatalyst for high-energy-density lithium-sulfur batteries[J]. J. Am. Chem. Soc., 2022, 144(32): 14638-14646. doi: 10.1021/jacs.2c04176 URL
[56]	Xie J, Song Y W, Li B Q, Peng H J, Huang J Q, Zhang Q. Direct intermediate regulation enabled by sulfur containers in working lithium-sulfur batteries[J]. Angew. Chem. Int. Ed., 2020, 59(49): 22150-22155. doi: 10.1002/anie.202008911 URL
[57]	Li X Y, Zhang Q. One stone two birds: Dual-effect kinetic regulation strategy for practical lithium-sulfur batteries[J]. J. Energy Chem., 2022, 65: 302-303. doi: 10.1016/j.jechem.2021.05.039 URL
[58]	Zhao M, Chen X, Li X Y, Li B Q, Huang J Q. An organodiselenide comediator to facilitate sulfur redox kinetics in lithium-sulfur batteries[J]. Adv. Mater., 2021, 33(13): 2007298. doi: 10.1002/adma.202007298 URL
[59]	Zhao M, Li X Y, Chen X, Li B Q, Kaskel S, Zhang Q, Huang J Q. Promoting the sulfur redox kinetics by mixed organodiselenides in high-energy-density lithium-sulfur batteries[J]. eScience, 2021, 1(1): 44-52. doi: 10.1016/j.esci.2021.08.001 URL
[60]	Chen X, Peng L F, Wang L H, Yang J Q, Hao Z X, Xiang J W, Yuan K, Huang Y H, Shan B, Yuan L X, Xie J. Ether-compatible sulfurized polyacrylonitrile cathode with excellent performance enabled by fast kinetics via selenium doping[J]. Nat. Commun., 2019, 10: 1021. doi: 10.1038/s41467-019-08818-6 pmid: 30833552
[61]	Zhao C X, Chen W J, Zhao M, Song Y W, Liu J N, Li B Q, Yuan T, Chen C M, Zhang Q, Huang J Q. Redox mediator assists electron transfer in lithium-sulfur batteries with sulfurized polyacrylonitrile cathodes[J]. EcoMat, 2021, 3(1): e12066.
[62]	Frey M, Zenn R K, Warneke S, Müller K, Hintennach A, Dinnebier R E, Buchmeiser M R. Easily accessible, textile fiber-based sulfurized poly(acrylonitrile) as Li/S cathode material: Correlating electrochemical performance with morphology and structure[J]. ACS Energy Lett., 2017, 2(3): 595-604. doi: 10.1021/acsenergylett.7b00009 URL
[63]	Razzaq A A, Yao Y Z, Shah R, Qi P W, Miao L X, Chen M Z, Zhao X H, Peng Y, Deng Z. High-performance lithium sulfur batteries enabled by a synergy between sulfur and carbon nanotubes[J]. Energy Storage Mater., 2019, 16: 194-202.
[64]	Wang X F, Qian Y M, Wang L N, Yang H, Li H L, Zhao Y, Liu T X. Sulfurized polyacrylonitrile cathodes with high compatibility in both ether and carbonate electrolytes for ultrastable lithium-sulfur batteries[J]. Adv. Funct. Mater., 2019, 29(39): 1902929. doi: 10.1002/adfm.201902929 URL
[65]	Li S P, Han Z L, Hu W, Peng L F, Yang J Q, Wang L H, Zhang Y Y, Shan B, Xie J. Manipulating kinetics of sulfurized polyacrylonitrile with tellurium as eutectic accelerator to prevent polysulfide dissolution in lithium-sulfur battery under dissolution-deposition mechanism[J]. Nano Energy, 2019, 60: 153-161. doi: 10.1016/j.nanoen.2019.03.023 URL
[66]	Lebherz T, Frey M, Hintennach A, Buchmeiser M R. Influence of morphology of monolithic sulfur-poly(acrylonitrile) composites used as cathode materials in lithium-sulfur batteries on electrochemical performance[J]. RSC Adv., 2019, 9(13): 7181-7188. doi: 10.1039/c8ra09976f
[67]	Zhou J J, Guo Y S, Liang C D, Cao L J, Pan H, Yang J, Wang J L. A new ether-based electrolyte for lithium sulfur batteries using a S@pPAN cathode[J]. Chem. Commun., 2018, 54(43): 5478-5481. doi: 10.1039/C8CC02552E URL
[68]	Yin L C, Wang J L, Lin F J, Yang J, Nuli Y. Polyacrylonitrile/graphene composite as a precursor to a sulfur-based cathode material for high-rate rechargeable Li-S batteries[J]. Energy Environ. Sci., 2012, 5(5): 6966-6972. doi: 10.1039/c2ee03495f URL
[69]	Yang H J, Chen J H, Yang J, Wang J L. Prospect of sulfurized pyrolyzed poly(acrylonitrile) (S@pPAN) cathode materials for rechargeable lithium batteries[J]. Angew. Chem. Int. Ed., 2020, 59(19): 7306-7318. doi: 10.1002/anie.201913540 pmid: 31713966
[70]	Li Z, Zhang J T, Lu Y, Lou X W. A pyrolyzed polyacrylonitrile/selenium disulfide composite cathode with remarkable lithium and sodium storage performances[J]. Sci. Adv., 2018, 4(6): eaat1687. doi: 10.1126/sciadv.aat1687 URL
[71]	Wang L H, Chen X, Li S P, Yang J Q, Sun Y L, Peng L F, Shan B, Xie J. Effect of eutectic accelerator in selenium-doped sulfurized polyacrylonitrile for high performance room temperature sodium-sulfur batteries[J]. J. Mater. Chem. A, 2019, 7(20): 12732-12739. doi: 10.1039/C9TA02831E URL

	Component	Sulfur loading (mg_S·cm^-2)	Specific capacity(mAh·g^-1)	Cycling lifespan	Reference
S/C cathode	G@ppy-por	5.0	940 @0.2 C	70 @0.2 C	Zhao et al.^[40]
	MoS₂ with TEA	4.0	988 @0.3 C	100 @0.3 C	Li et al.^[37]
	DPDSe	5.0	924 @0.1 C	55 @0.1 C	Zhao et al.^[58]
	LPC	4.0	1001 @0.1 C	100 @0.1 C	Feng et al.^[39]
	7TiN:3TiO₂-G	1.2	800 @1.0 C	2000 @1.0 C	Zhou et al.^[51]
	Co₄N/NG	4.1	1109 @0.5 C	150 @0.5 C	Zhao et al.^[53]
SPAN cathode	Se_0.06SPAN	1 ~ 3	1240 @0.26 C	800 @0.26 C	Chen et al.^[60]
	BEAQ	1.5	1109 @1.0 C	160 @1.0 C	Zhao et al.^[61]
	Fibrous SPAN	0.672	600 @4.0 C	1000 @4.0 C	Frey et al.^[62]
	SPAN-CNT20	0.9 ~ 1.1	1106 @1.0 C	500 @1.0 C	Razzaq et al.^[63]
	SPAN/CNT-12	2.0	1180 @0.48 C	1000 @0.48 C	Wang et al.^[64]
	Te_0.04S_0.96@pPAN	3.11	870 @0.12 C	100 @0.12 C	Li et al.^[65]