全钒液流电池（VRFB）作为一种新型储能电池，具有设计灵活、高效、循环寿命 长、安全、环保等多重优点，可广泛应用于电网调峰、可再生能源发电以及军用蓄电等 领域。石墨毡材料由于其导电性良好、稳定性高以及孔隙率大等特点，成为 VRFB 中应 用最广泛的电极材料。然而，石墨毡（GF）电化学活性较差，对正负极反应特别是负 极反应催化性能不足，正负极析氧析氢现象较为显著。为了解决上述问题，本文拟出在 石墨毡上包覆钛氧化合物作为催化剂催化电极反应，同时抑制析氢析氧。第三章中，通 过水热与氢还原方法在电极表面包覆了氧空位 TiO₂。在第四章中，在第三章的基础上 进一步优化工艺，成功合成了 Magnéli 相电极。最后，在第五章中，我们采用了异价离 子掺杂和低温还原方法，成功合成了 Nb_xTi_1-xO₂/石墨毡复合电极。

  首先通过引入氧空位来调节 TiO2 的表面电子分布，增强电极 VO₂ ⁺ /VO²⁺和 V³⁺/V²⁺ 氧化还原反应的催化能力，并同时抑制有害的副反应（HER 和 OER）。由于增强的催化 活性和选择性，1000-TiO2-GF 电极在小电流下展示出接近 90%的钒利用率。此外， 1000-TiO₂-GF 电极在 120 mA/cm² 下稳定运行了 200 个循环，没有明显的效率下降。密 度泛函理论（DFT）结果表明，TiO2 中的氧空位为其相邻的钛提供了额外电子，进一步 加强了富电子的钛与 VO₂ ⁺ /VO²⁺中氧之间的相互作用，从而增强其吸附和催化性能。氧 空位丰富的 TiO₂涂层对 V³⁺/V²⁺的增强催化活性则可归因于对析氢反应的有效抑制。

  为了进一步提高 TiO₂ 包覆层的电导率，进一步优化了还原过程，成功制备了 Magn éli 相，纯 Ti₃O₅ 和 Ti₄O₇ 相包覆石墨毡电极。Ti₄O₇-GF、Ti₃O₅-GF 电极能够有效地同时 催化 VO₂ ⁺ /VO²⁺和 V³⁺/V²⁺的氧化还原反应，并抑制正极的氧气析出反应和负极的氢气 析出反应，其中以 Ti4O7-GF 电极催化性能最佳。使用 Ti₄O₇-GF 组装的 VRFB 在 120 mA/cm² 下稳定运行 100 个循环，没有出现明显的效率下降，在电流密度为 180 mA/cm² 时，Ti₄O₇-GF 电极的电压效率和能量效率分别比 GF 电极高出 18%和 19%。

  最后，为进一步降低电极极化，提升能量效率，同时采用高价阳离子掺杂和低温氢 还原的策略。通过水热法+氢气还原制备铌掺杂钛氧化合物包覆石墨毡电极。随着氢气 还原温度的升高锐钛矿 TiO₂ 会向金红石 TiO₂ 转变。氢还原 Nb 掺杂 TiO₂ 包覆的石墨毡电极能够有效地同时催化 VO₂ ⁺ /VO²⁺和 V³⁺/V²⁺的氧化还原反应，并抑制正极的氧气析出反应和负极的氢气析出反应。在 135 mA/cm² 下，经 800℃还原的 Nb-TiO²-GF 电极表 现出高达 80%的电压效率，并在 120 mA/cm² 下稳定运行 100 个循环，没有出现明显的效率下降。

The vanadium redox flow battery (VRFB), as a novel energy storage battery, possesses

multiple advantages such as flexible design, high efficiency, long cycle life, safety, and

environmental friendliness, making it suitable for a wide range of applications including grid

peak shaving, renewable energy generation, and military storage. Graphite felt (GF), due to its

excellent conductivity, high stability, and large porosity, has become the most widely used

electrode material in VRFBs. However, GF exhibits poor electrochemical activity, particularly

in catalyzing electrode reactions, leading to significant oxygen and hydrogen evolution at both

positive and negative electrodes. To address these issues, this study proposes the coating of

titanium oxides on graphite felt to catalyze electrode reactions while suppressing hydrogen and

oxygen evolution. In Chapter Three, oxygen-vacancy TiO2 was coated on the electrode surface

by hydrothermal and hydrogen reduction methods. In Chapter Four, building upon the findings

of Chapter Three, we further optimized the process and successfully synthesized Magnéli phase

electrodes. Finally, in Chapter Five, we adopted strategies involving heterovalent ion doping

and low-temperature reduction to synthesize NbxTi1-xO2/graphite felt composite electrodes.

By introducing oxygen vacancies to modulate the surface electronic distribution of TiO2,

we enhanced the catalytic ability of the electrode for VO2 + /VO2+ and V3+/V2+ oxidation

reduction reactions while inhibiting detrimental side reactions (HER and OER). Due to the

enhanced catalytic activity and selectivity, the 1000-TiO2-GF electrode demonstrated close to

90% vanadium utilization at low currents. Additionally, the 1000-TiO2-GF electrode exhibited

stable operation for 200 cycles at 120 mA/cm2 without significant efficiency degradation. Density functional theory (DFT) results showed that oxygen vacancies in TiO2 provided

additional electrons to neighboring titanium, further strengthening the interaction between

electron-rich titanium and oxygen in VO2 + /VO2+, thereby enhancing its adsorption and catalytic

performance. The abundant oxygen vacancies in TiO2 coating contributed to the enhanced

catalytic activity for V3+/V2+ and effectively suppressed hydrogen evolution reaction.

To further improve the electrical conductivity of the TiO2 coating, we optimized the

reduction process and successfully prepared Magnéli phase electrodes, including pure Ti3O5 and

Ti4O7 phase-coated graphite felt electrodes. The Ti4O7-GF and Ti3O5-GF electrodes effectively

catalyzed both VO2 + /VO2+ and V3+/V2+ oxidation-reduction reactions while suppressing oxygen

evolution at the positive electrode and hydrogen evolution at the negative electrode, with Ti4O7-

GF electrode exhibiting the best catalytic performance. The VRFB assembled with Ti4O7-GF

operated stably for 100 cycles at 120 mA/cm2 without significant efficiency degradation, and at

a current density of 180 mA/cm2 , the voltage efficiency and energy efficiency of the Ti4O7-GF

electrode were 18% and 19% higher, respectively, compared to the GF electrode.

Finally, to further reduce electrode polarization and enhance energy efficiency, a strategy

involving high-valence cation doping and low-temperature hydrogen reduction was employed.

Niobium-doped titanium oxide compounds were prepared by hydrothermal treatment followed

by hydrogen reduction to coat the graphite felt electrode. As the temperature of hydrogen

reduction increased, the rutile TiO2 transformed into anatase TiO2. The graphite felt electrode

coated with hydrogen-reduced Nb-doped TiO2 effectively catalyzed the oxidation-reduction

reactions of both VO2 + /VO2+ and V3+/V2+, while suppressing oxygen evolution at the positive

electrode and hydrogen evolution at the negative electrode. At 135 mA/cm2 , the Nb-TiO2-GF

electrode reduced at 800°C exhibited voltage efficiency as high as 80%, and it operated stably

for 100 cycles at 120 mA/cm2 without significant efficiency degradation.

[1] Chu S, Majumdar A. Opportunities, and challenges for a sustainable energy future[J]. Nature, 2012, 488(7411): 294-303.

[2] Dunn B, Kamath H, Tarascon J M. Electrical energy storage for the grid: a battery of choices[J]. Science, 2011, 334(6058): 928-935.

[3] Yang Z, Zhang J, Kintner-Meyer M C W, et al. Electrochemical energy storage for green grid[J]. Chemical Reviews, 2011, 111(5): 3577-3613.

[4] 张华民. 储能与液流电池技术[J]. 储能科学与技术, 2012, 1(1): 58-63.

[5] Ravikumar M K, Rathod S, Jaiswal N, et al. The renaissance in redox flow batteries[J]. Journal of Solid State Electrochemistry, 2017, 21: 2467-2488.

[6] Park M, Ryu J, Wang W, et al. Material design and engineering of next-generation flow-battery technologies[J]. Nature Reviews Materials, 2016, 2(1): 1-18.

[7] Sum E, Skyllas-Kazacos M. A study of the V (II)/V (III) redox couple for redox flow cell applications[J]. Journal of Power sources, 1985, 15(2-3): 179-190.

[8] Sum E, Rychcik M, Skyllas-Kazacos M. Investigation of the V (V)/V (IV) system for use in the positive half-cell of a redox battery[J]. J. Power Sources, 1985, 16(2): 19-26.

[9] Kim K J, Park M S, Kim Y J, et al. A technology review of electrodes and reaction mechanisms in vanadium redox flow batteries[J]. Journal of materials chemistry a, 2015, 3(33): 16913-16933.

[10] Mehboob S, Ali G, Shin H J, et al. Enhancing the performance of all-vanadium redox flow batteries by decorating carbon felt electrodes with SnO2 nanoparticles[J]. Applied Energy, 2018, 229: 910-921.

[11] Sun P G Y, You W, Tan Z. Studies on an iron heteropolyacid redox flow battery[J]. Journal of Electrochemistry, 1997, 3(1): 3-14.

[12] Skyllas‐Kazacos M, Grossmith F. Efficient vanadium redox flow cell[J]. Journal of the Electrochemical Society, 1987, 134(12): 2950-2959.

[13] Bartolozzi M. Development of redox flow batteries. A historical bibliography[J]. Journal of Power Sources, 1989, 27(3): 219-234.

[14] Alotto P, Guarnieri M, Moro F. Redox flow batteries for the storage of renewable energy: A review[J]. Renewable and sustainable energy reviews, 2014, 29: 325-335.

[15] Ding C, Zhang H, Li X, et al. Vanadium flow battery for energy storage: prospects and challenges[J]. The journal of physical chemistry letters, 2013, 4(8): 1281-1294.

[16] Kazacos M, Cheng M, Skyllas-Kazacos M. Vanadium redox cell electrolyte optimization studies[J]. Journal of Applied electrochemistry, 1990, 20(3): 463-467.

[17] 王绍亮, 范新庄, 张建国, 等. 钒电池电解液配比的优化及其对电池性能的影响[J]. 储能科学与技术, 2015, 4(5): 510-514.

[18] Rahman F, Skyllas-Kazacos M. Solubility of vanadyl sulfate in concentrated sulfuric acid solutions[J]. Journal of Power Sources, 1998, 72(2): 105-110.

[19] 赵建新, 武增华, 席靖宇, 等. Solubility rules of negative electrolyte V2(SO4)3 of vanadium redox flow battery[J]. 无机材料学报, 2012, 27(5): 469-474.

[20] Vijayakumar M, Burton S D, Huang C, et al. Nuclear magnetic resonance studies on vanadium (IV) electrolyte solutions for vanadium redox flow battery[J]. Journal of Power Sources, 2010, 195(22): 7709-7717.

[21] Vijayakumar M, Li L, Nie Z, et al. Structure and stability of hexa-aqua V (III) cations in vanadium redox flow battery electrolytes[J]. Physical Chemistry Chemical Physics, 2012, 14(29): 10233-10242.

[22] Vijayakumar M, Li L, Graff G, et al. Towards understanding the poor thermal stability of V5+ electrolyte solution in vanadium redox flow batteries[J]. Journal of Power Sources, 2011, 196(7): 3669-3672.

[23] Prifti H, Parasuraman A, Winardi S, et al. Membranes for redox flow battery applications[J]. Membranes, 2012, 2(2): 275-306.

[24] Li X, Zhang H, Mai Z, et al. Ion exchange membranes for vanadium redox flow battery (VRB) applications[J]. Energy & Environmental Science, 2011, 4(4): 1147-1160.

[25] Xi J, Wu Z, Qiu X, et al. Nafion/SiO2 hybrid membrane for vanadium redox flow battery[J]. Journal of Power Sources, 2007, 166(2): 531-536.

[26] Xi J, Wu Z, Teng X, et al. Self-assembled polyelectrolyte multilayer modified Nafion membrane with suppressed vanadium ion crossover for vanadium redox flow batteries[J]. Journal of Materials Chemistry, 2008, 18(11): 1232-1238.

[27] Luo Q, Zhang H, Chen J, et al. Preparation and characterization of Nafion/SPEEK layered composite membrane and its application in vanadium redox flow battery[J]. Journal of Membrane Science, 2008, 325(2): 553-558.

[28] Teng X, Sun C, Dai J, et al. Solution casting Nafion/polytetrafluoroethylene membrane for vanadium redox flow battery application[J]. Electrochimica Acta, 2013, 88: 725-734.

[29] Jiang B, Wu L, Yu L, et al. A comparative study of Nafion series membranes for vanadium redox flow batteries[J]. Journal of Membrane Science, 2016, 510: 18-26.

[30] Jiang B, Yu L, Wu L, et al. Insights into the impact of the nafion membrane pretreatment process on vanadium flow battery performance[J]. ACS applied materials & interfaces, 2016, 8(19): 12228-12238.

[31] Xi J, Jiang B, Yu L, et al. Membrane evaluation for vanadium flow batteries in a temperature range of− 20–50℃[J]. Journal of membrane science, 2017, 522: 45-55.

[32] Li Z, Xi J, Zhou H, et al. Preparation and characterization of sulfonated poly (ether ether ketone)/poly (vinylidene fluoride) blend membrane for vanadium redox flow battery application[J]. Journal of Power Sources, 2013, 237: 132-140.

[33] Dai W, Shen Y, Li Z, et al. SPEEK/Graphene oxide nanocomposite membranes with superior cyclability for highly efficient vanadium redox flow battery[J]. Journal of Materials Chemistry A, 2014, 2(31): 12423-12432.

[34] Hoang T K A, Chen P. Recent development of polymer membranes as separators for all-vanadium redox flow batteries[J]. RSC Advances, 2015, 5(89): 72805-72815.

[35] Huang K L, Li X, Liu S, et al. Research progress of vanadium redox flow battery for energy storage in China[J]. Renewable Energy, 2008, 33(2): 186-192.

[36] Fang B, Wei Y, Arai T, et al. Development of a novel redox flow battery for electricity storage system[J]. Journal of Applied Electrochemistry, 2003, 33(2): 197-203.

[37] Tokuda N, Kumamoto T, Shigematsu T, et al. Development of a redox flow battery system[J]. SUMITOMO ELECTRIC TECHNICAL REVIEW-ENGLISH EDITION-, 1998: 88-94.

[38] Skyllas‐Kazacos M, Peng C, Cheng M. Evaluation of precipitation inhibitors for supersaturated vanadyl electrolytes for the vanadium redox battery[J]. Electrochemical and solid-state letters, 1998, 2(3): 121-128.

[39] Rychcik M, Skyllas-Kazacos M. Evaluation of electrode materials for vanadium redox cell[J]. Journal of Power Sources, 1987, 19(1): 45-54.

[40] Noack J, Roznyatovskaya N, Kunzendorf J, et al. The influence of electrochemical treatment on electrode reactions for vanadium redox-flow batteries[J]. Journal of Energy Chemistry, 2018, 27(5): 1341-1352.

[41] He Z, Chen Z, Meng W, et al. Modified carbon cloth as positive electrode with high electrochemical performance for vanadium redox flow batteries[J]. Journal of Energy Chemistry, 2016, 25(4): 720-725.

[42] Jiang Y, Feng X, Cheng G, et al. Electrocatalytic activity of MnO2 nanosheet array-decorated carbon paper as superior negative electrode for vanadium redox flow batteries[J]. Electrochimica Acta, 2019, 322: 134754.

[43] Wei G, Su W, Wei Z, et al. Effect of the graphitization degree for electrospun carbon nanofibers on their electrochemical activity towards VO2+/VO2+ redox couple[J]. Electrochimica Acta, 2016, 199: 147-153.

[44] Sun B, Skyllas-Kazacos M. Modification of graphite electrode materials for vanadium redox flow battery application—I. Thermal treatment[J]. Electrochimica acta, 1992, 37(7): 1253-1260.

[45] Kabtamu D M, Chen J Y, Chang Y C, et al. Water-activated graphite felt as a high-performance electrode for vanadium redox flow batteries[J]. Journal of Power Sources, 2017, 341: 270-279.

[46] He Z, Jiang Y, Zhou H, et al. Graphite felt electrode modified by square wave potential pulse for vanadium redox flow battery[J]. International Journal of Energy Research, 2017, 41(3): 439-447.

[47] Li B, Gu M, Nie Z, et al. Bismuth nanoparticle decorating graphite felt as a high-performance electrode for an all-vanadium redox flow battery[J]. Nano letters, 2013, 13(3): 1330-1335.

[48] Wei L, Zhao T S, Zeng L, et al. Copper nanoparticle-deposited graphite felt electrodes for all vanadium redox flow batteries[J]. Applied Energy, 2016, 180: 386-391.

[49] Wang W H, Wang X D. Investigation of Ir-modified carbon felt as the positive electrode of an all-vanadium redox flow battery[J]. Electrochimica Acta, 2007, 52(24): 6755-6762.

[50] Wei L, Zhao T S, Zeng L, et al. Highly catalytic and stabilized titanium nitride nanowire array-decorated graphite felt electrodes for all vanadium redox flow batteries[J]. Journal of Power Sources, 2017, 341: 318-326.

[51] Li G R, Wang F, Song J, et al. TiN-conductive carbon black composite as counter electrode for dye-sensitized solar cells[J]. Electrochimica Acta, 2012, 65: 216-220.

[52] Ma J, Sahai Y, Buchheit R G. Direct borohydride fuel cell using Ni-based composite anodes[J]. Journal of Power Sources, 2010, 195(15): 4709-4713.

[53] Yang C, Wang H, Lu S, et al. Titanium nitride as an electrocatalyst for V (II)/V (III) redox couples in all-vanadium redox flow batteries[J]. Electrochimica Acta, 2015, 182: 834-840.

[54] González Z, Flox C, Blanco C, et al. Outstanding electrochemical performance of a graphene-modified graphite felt for vanadium redox flow battery application[J]. Journal of Power Sources, 2017, 338: 155-162.

[55] Chang Y C, Shih Y C, Chen J Y, et al. High efficiency of bamboo-like carbon nanotubes on functionalized graphite felt as electrode in vanadium redox flow battery[J]. RSC advances, 2016, 6(104): 102068-102075.

[56] Kabtamu D M, Li Y Z, Bayeh A W, et al. BiVO4-Decorated Graphite Felt as Highly Efficient Negative Electrode for All-Vanadium Redox Flow Batteries[J]. ACS Applied Energy Materials, 2023, 6(6): 3301-3311.

[57] Wu X, Xu H, Lu L, et al. PbO2-modified graphite felt as the positive electrode for an all-vanadium redox flow battery[J]. Journal of Power Sources, 2014, 250: 274-278.

[58] Zhou H, Shen Y, Xi J, et al. ZrO2-nanoparticle-modified graphite felt: bifunctional effects on vanadium flow batteries[J]. ACS applied materials & interfaces, 2016, 8(24): 15369-15378.

[59] Shen Y, Xu H, Xu P, et al. Electrochemical catalytic activity of tungsten trioxide-modified graphite felt toward VO2+/VO2+ redox reaction[J]. Electrochimica Acta, 2014, 132: 37-41.

[60] Lv Y, Han C, Zhu Y, et al. Recent advances in metals and metal oxides as catalysts for vanadium redox flow battery: Properties, structures, and perspectives[J]. Journal of Materials Science & Technology, 2021, 75: 96-109.

[61] Zhang W, Du M, Xi W, et al. Platinum species on oxygen vacancy-rich titania for efficient basic electrocatalytic hydrogen evolution[J]. Langmuir, 2023, 39(36): 12715-12724.

[62] Chen L N, Wang S H, Zhang P Y, et al. Ru nanoparticles supported on partially reduced TiO2 as highly efficient catalyst for hydrogen evolution[J]. Nano Energy, 2021, 88: 106211-106218.

[63] Lu Y, Yin W J, Peng K L, et al. Self-hydrogenated shell promoting photocatalytic H2 evolution on anatase TiO2[J]. Nature communications, 2018, 9(1): 2752-2761.

[64] Guo Y, Chen S, Yu Y, et al. Hydrogen-location-sensitive modulation of the redox reactivity for oxygen-deficient TiO2[J]. Journal of the American Chemical Society, 2019, 141(21): 8407-8411.

[65] Jia G, Wang Y, Cui X, et al. Wet-chemistry hydrogen doped TiO2 with switchable defects control for photocatalytic hydrogen evolution[J]. Matter, 2022, 5(1): 206-218.

[66] Cao G, Yi N. Quantitative Analysis of Anatase‐Rutile Mixtures by Raman Spectroscopy[J]. ChemistrySelect, 2020, 5(37): 11530-11533.

[67] Xiao F, Zhou W, Sun B, et al. Engineering oxygen vacancy on rutile TiO2 for efficient electron-hole separation and high solar-driven photocatalytic hydrogen evolution[J]. Sci China Mater, 2018, 61: 822-830.

[68] Tang Z, Li Y, Zhang K, et al. Interfacial Hydrogen Spillover on Pd-TiO2 with Oxygen Vacancies Promotes Formate Electrooxidation[J]. ACS Energy Letters, 2023, 8(9): 3945-3954.

[69] Naldoni A, Altomare M, Zoppellaro G, et al. Photocatalysis with reduced TiO2: from black TiO2 to cocatalyst-free hydrogen production[J]. ACS catalysis, 2018, 9(1): 345-364.

[70] Pan X, Yang M Q, Fu X, et al. Defective TiO2 with oxygen vacancies: synthesis, properties and photocatalytic applications[J]. Nanoscale, 2013, 5(9): 3601-3614.

[71] Morgan B J, Watson G W. Intrinsic n-type defect formation in TiO2: a comparison of rutile and anatase from GGA+ U calculations[J]. The Journal of Physical Chemistry C, 2010, 114(5): 2321-2328.

[72] Kim C, Park S O, Kwak S K, et al. Concurrent oxygen reduction and water oxidation at high ionic strength for scalable electrosynthesis of hydrogen peroxide[J]. Nature Communications, 2023, 14(1): 5822-5829.

[73] Li H, Shang J, Ai Z, et al. Efficient visible light nitrogen fixation with BiOBr nanosheets of oxygen vacancies on the exposed {001} facets[J]. Journal of the American Chemical Society, 2015, 137(19): 6393-6399.

[74] Bao J, Zhang X, Fan B, et al. Ultrathin spinel‐structured nanosheets rich in oxygen deficiencies for enhanced electrocatalytic water oxidation[J]. Angewandte Chemie, 2015, 127(25): 7507-7512.

[75] Trasatti S. Work function, electronegativity, and electrochemical behaviour of metals: III. Electrolytic hydrogen evolution in acid solutions[J]. Journal of Electroanalytical Chemistry and Interfacial Electrochemistry, 1972, 39(1): 163-184.

[76] Nørskov J K, Bligaard T, Logadottir A, et al. Trends in the exchange current for hydrogen evolution[J]. Journal of The Electrochemical Society, 2005, 152(3): J23- J29.

[77] Kim K J, Kim Y J, Kim J H, et al. The effects of surface modification on carbon felt electrodes for use in vanadium redox flow batteries[J]. Materials Chemistry and Physics, 2011, 131(1-2): 547-553.

[78] Zhang W, Xi J, Li Z, et al. Electrochemical activation of graphite felt electrode for VO2+/VO2+ redox couple application[J]. Electrochimica Acta, 2013, 89: 429-435.

[79] Kim Y, Choi Y Y, Yun N, et al. Activity gradient carbon felt electrodes for vanadium redox flow batteries[J]. Journal of Power Sources, 2018, 408: 128-135.

[80] Zhang X, Valencia A, Li W, et al. Decoupling Activation and Transport by Electron‐Regulated Atomic‐Bi Harnessed Surface‐to‐Pore Interface for Vanadium Redox Flow Battery[J]. Advanced Materials, 2024, 36(6): 2305415-2305427.

[81] Jiang Y, Liu Z, Lv Y, et al. Perovskite enables high performance vanadium redox flow battery[J]. Chemical Engineering Journal, 2022, 443: 136341-136349.

[82] Thoa T T, Nguyen T T, Van Hung H, et al. Slab models of rutile TiO2 (110) surface: DFT and DFT+ U calculations[J]. Vietnam Journal of Chemistry, 2023, 61(5): 563-570.

[83] Liang X, Hart C, Pang Q, et al. A highly efficient polysulfide mediator for lithium–sulfur batteries[J]. Nature communications, 2015, 6(1): 5682-5691.

[84] Zhao Z, Duan X, Zhang L, et al. Elevated electrochemical performances enabled by a core–shell titanium hydride coated separator in lithium–sulphur batteries[J]. RSC advances, 2021, 11(49): 30755-30762.

[85] Wang Z, Han R, Huang D, et al. Co-Intercalation-Free Ether-Based Weakly Solvating Electrolytes Enable Fast-Charging and Wide-Temperature Lithium-Ion Batteries[J]. ACS nano, 2023, 17(18): 18103-18113.

[86] Zeng F, Li S, Hu S, et al. Weak Solvation Effect Enhancing Capacity and Rate Performance of Vanadium‐Based Calcium Ion Batteries: A Strategy Guided by Donor Number[J]. Advanced functional materials, 2024, 34(5): 2302397-2302406.

[87] Yang H, Chen D, Zhao R, et al. Reunderstanding aqueous Zn electrochemistry from interfacial specific adsorption of solvation structures[J]. Energy & Environmental Science, 2023, 16(7): 2910-2923.

[88] Wang Y, Ma Z, Cao Z, et al. Unraveling New Role of Binder Functional Group as a Probe to Detect Dynamic Lithium‐Ion De‐Solvation Process toward High Electrode Performances[J]. Advanced Functional Materials, 2023, 33(45): 2305974-2305982.

[89] Zhang X, Li X, Zhang Y, et al. Accelerated Li+ Desolvation for Diffusion Booster Enabling Low‐Temperature Sulfur Redox Kinetics via Electrocatalytic Carbon‐Grazfted‐CoP Porous Nanosheets[J]. Advanced Functional Materials, 2023, 33(36): 2302624-2302632.

[90] Zhao C, Lin Y, Lin Q, et al. CP/C= O bonds assisted desolvation effect in ultra-micropores carbon for boosting Zn-ion storage capability[J]. Energy Storage Materials, 2023, 58: 332-343.

[91] Li L, Tu H, Wang J, et al. Electrocatalytic MOF‐Carbon Bridged Network Accelerates Li+‐Solvents Desolvation for High Li+ Diffusion toward Rapid Sulfur Redox Kinetics[J]. Advanced Functional Materials, 2023, 33(13): 2212499-2212508.

[92] Portehault D, Maneeratana V, Candolfi C, et al. Facile general route toward tunable Magnéli nanostructures and their use as thermoelectric metal oxide/carbon nanocomposites[J]. ACS nano, 2011, 5(11): 9052-9061.

[93] T Takimoto D, Toda Y, Tominaka S, et al. Conductive nanosized Magnéli-phase Ti4O7 with a core@ shell structure[J]. Inorganic Chemistry, 2019, 58(10): 7062-7068.

[94] Ibrahim K B, Su W N, Tsai M C, et al. Robust and conductive Magnéli Phase Ti4O7 decorated on 3D-nanoflower NiRu-LDH as high-performance oxygen reduction electrocatalyst[J]. Nano Energy, 2018, 47: 309-315.

[95] Li X, Zhu A L, Qu W, et al. Magneli phase Ti4O7 electrode for oxygen reduction reaction and its implication for zinc-air rechargeable batteries[J]. Electrochimica Acta, 2010, 55(20): 5891-5898.

[96] Maneeratana V, Portehault D, Chaste J, et al. Original electrospun core-shell nanostructured Magnéli titanium oxide fibers and their electrical properties[J]. Advanced Materials (Deerfield Beach, Fla.), 2014, 26(17): 2654-8, 2614.

[97] Si P, Li M, Wang X, et al. Origin of Enhanced Electricity Generation on Magnéli Phase Titanium Suboxide Nanocrystal Films[J]. ACS Applied Energy Materials, 2021, 4(10): 10877-10885.

[98] Kabtamu D M, Chen J Y, Chang Y C, et al. Electrocatalytic activity of Nb-doped hexagonal WO3 nanowire-modified graphite felt as a positive electrode for vanadium redox flow batteries[J]. Journal of Materials Chemistry A, 2016, 4(29): 11472-11480.

[99] Chen Y, Mao J. Sol–gel preparation and characterization of black titanium oxides Ti2O3 and Ti3O5[J]. Journal of Materials Science: Materials in Electronics, 2014, 25: 1284-1288.

[100] Cabaret D, Joly Y, Renevier H. Pre-edge structure analysis of Ti K-edge polarized X-ray absorption spectra in TiO2 by full-potential XANES calculations[J]. Journal of Synchrotron Radiation, 1999, 6(3): 258-260.

[101] Lin H, Xiao R, Xie R, et al. Defect engineering on a Ti4O7 electrode by Ce3+ doping for the efficient electrooxidation of perfluorooctanesulfonate[J]. Environmental Science & Technology, 2021, 55(4): 2597-2607.

[102] Guo Y, Li J, Pitcheri R, et al. Electrospun Ti4O7/C conductive nanofibers as interlayer for lithium-sulfur batteries with ultra long cycle life and high-rate capability[J]. Chemical Engineering Journal, 2019, 355: 390-398.

[103] Tang Z, Zou J, Zhang D, et al. TixOy loaded carbon felt as high performance negative for vanadium redox flow battery[J]. Journal of Power Sources, 2023, 566: 232925-232932.

[104] Li Y, Ma L, Yi Z, et al. Metal–organic framework-derived carbon as a positive electrode for high-performance vanadium redox flow batteries[J]. Journal of Materials Chemistry A, 2021, 9(9): 5648-5656.

[105] Derr I, Bruns M, Langner J, et al. Degradation of all-vanadium redox flow batteries (VRFB) investigated by electrochemical impedance and X-ray photoelectron spectroscopy: Part 2 electrochemical degradation[J]. Journal of Power Sources, 2016, 325: 351-359.

[106] Taylor S M, Pătru A, Fabbri E, et al. Influence of surface oxygen groups on V (II) oxidation reaction kinetics[J]. Electrochemistry Communications, 2017, 75: 13-16.

[107] Potlog T, Dumitriu P, Dobromir M, et al. Nb-doped TiO2 thin films for photovoltaic applications[J]. Materials & Design, 2015, 85: 558-563.

[108] Hitosugi T, Kamisaka H, Yamashita K, et al. Electronic band structure of transparent conductor: Nb-doped anatase TiO2[J]. Applied physics express, 2008, 1(11): 111203-111215.

[109] Zhang W F, He Y L, Zhang M S, et al. Raman scattering study on anatase TiO2 nanocrystals[J]. Journal of Physics D: Applied Physics, 2000, 33(8): 912-921.

[110] Frank O, Zukalova M, Laskova B, et al. Raman spectra of titanium dioxide (anatase, rutile) with identified oxygen isotopes (16, 17, 18) [J]. Physical Chemistry Chemical Physics, 2012, 14(42): 14567-14572.

[111] Secundino-Sánchez O, Diaz-Reyes J, Sánchez-Ramírez J F, et al. Structural and optical characterization of the crystalline phase transformation of electrospinning TiO2 nanofibres by high temperatures annealing[J]. Revista mexicana de física, 2019, 65(5): 459-467.

[112] Horie Y, Watanabe T, Deguchi M, et al. Enhancement of carrier mobility by electrospun nanofibers of Nb-doped TiO2 in dye sensitized solar cells[J]. Electrochimica Acta, 2013, 105: 394-402.

[113] Liu Y, Liu M, Lan T, et al. One-step hydrothermal synthesis of Nb doped brookite TiO2 nanosheets with enhanced lithium-ion intercalation properties[J]. Journal of Materials Chemistry A, 2015, 3(37): 18882-18888.

[114] Hwang K, Sohn H, Yoon S. Mesostructured niobium-doped titanium oxide-carbon (Nb-TiO2-C) composite as an anode for high-performance lithium-ion batteries[J]. Journal of Power Sources, 2018, 378: 225-234