Structural engineering of MXenes towards high electrochemical performance in supercapacitors

Abstract

Supercapacitors (SCs) stand out among various energy storage devices owing to their high power density and long-term cycling stability. As new two-dimensional material, MXenes have become a research hotspot in recent years owing to their unique structure and rich surface functional groups. Compared with other materials, MXenes are more promising for SCs owing to their tunable precursors, structural stability, and excellent electrical conductivity. However, the rate performance and electrochemical reaction activity of MXene materials are poor, and stacking severely limits their application. Therefore, various modification strategies are employed to improve the electrochemical performance of MXene materials. As the modification strategy of MXene electrode materials often involves increasing the number of ion transport channels to expose more active sites, the packing density is also affected to different degrees. Therefore, achieving a balance between high volumetric capacitance and rapid ion transport has become a key issue for the application of MXene-based SCs in wearable devices and microdevices. In this paper, the latest progress in the preparation methods and modification strategies of MXenes in recent years is reviewed with the aim of achieving both high volumetric capacitance and high ion transport for expanding the application of MXene-based SCs in microdevices and wearable devices.

Keywords

MXenes / structural engineering / electrochemical performance / supercapacitor

References

[1] LuD, LiRH, RahmanMM, et al.. Ligand-channel-enabled ultrafast Li-ion conduction. Nature, 2024, 6278002101

[2] ZhangJJ, WuX. Dual-ion carrier storage through Mg²⁺ addition for high-energy and long-life zinc-ion hybrid capacitor. Int. J. Miner. Metall. Mater., 2024, 311179

[3] SichumsaengT, ChinnakornA, KalawaO, PadchasriJ, KidkhunthodP, MaensiriS. Comparative structural and electrochemical properties of mixed P2/O’3-layered sodium nickel manganese oxide prepared by sol–gel and electrospinning methods: Effect of Na-excess content. Int. J. Miner. Metall. Mater., 2023, 30101887

[4] E. Pomerantseva, F. Bonaccorso, X.L. Feng, Y. Cui, and Y. Gogotsi, Energy storage: The future enabled by nanomaterials, Science, 366(2019), No. 6468, art. No. eaan8285.

[5] G.W. Kim, S. Lee, G. Kim, H. Lee, K.T. Lee, and S.Y. Kim, Additive-free gelation of graphene oxide dispersions via mild thermal annealing: Implications for 3D printing and supercapacitor applications, Adv. Mater., 36(2024), No. 46, art. No. 2411479.

[6] XieB, HeJJ, ZhaoL, SunYC, LiSL, LiJ. Biomass activated carbon: The electrode material to promote the large-scale production of supercapacitors. Sci. Adv. Mater., 2023, 1591131

[7] X.B. Zang, J.L. Wang, Y.J. Qin, et al., Enhancing capacitance performance of Ti₃C₂T_x MXene as electrode materials of supercapacitor: From controlled preparation to composite structure construction, Nano Micro Lett., 12(2020), No. 1, art. No. 77.

[8] H.C. Hu, C.S. Deng, H. Gao, et al., 3D nanoprinting of heterogeneous metal oxides with high shape fidelity, Adv. Mater., 36(2024), No. 32, art. No. 2405053.

[9] X.Y. Chen, Q.F. Liu, L.K. Cheng, et al., Advanced electrochromic energy storage devices based on conductive polymers, Adv. Mater. Technol., 9(2024), No. 21, art. No. 2301969.

[10] FanLL, ZhengWF, YangY, et al.. Bacterial cellulose composites (MXene@TOBC@PPy) for flexible supercapacitors with improved electrochemical performance. Cellulose, 2023, 30106507

[11] K. Qi, Z.Z. Jin, D. Wang, Z.Y. Chen, X.P. Guo, and Y.B. Qiu, Insight into effect of electrolyte temperature on electroactivity degradation of conducting polypyrrole in NaOH, Polym. Degrad. Stab., 189(2021), art. No. 109593.

[12] ZhuQZ, LiJP, SimonP, XuB. Two-dimensional MXenes for electrochemical capacitor applications: Progress, challenges and perspectives. Energy Storage Mater., 2021, 35630

[13] ZhengZX, WuW, YangT, et al.. In situ reduced MXene/AuNPs composite toward enhanced charging/discharging and specific capacitance. J. Adv. Ceram., 2021, 1051061

[14] J.F. Li, Z.X. Yang, C.F. Wang, et al., Rapid electron transfer via hetero-interface engineering of 2D MOF anchored Ti₃C₂ MXene nanosheet for enhanced photocatalytic disinfection, Appl. Catal. B: Environ., 339(2023), art. No. 123163.

[15] R.A. Soomro, P. Zhang, B.M. Fan, Y. Wei, and B. Xu, Progression in the oxidation stability of MXenes, Nano-Micro Lett., 15(2023), No. 1, art. No. 108.

[16] F.C. Cao, Y. Zhang, H.Q. Wang, et al., Recent advances in oxidation stable chemistry of 2D MXenes, Adv. Mater., 34(2022), No. 13, art. No. 2107554.

[17] ChenRP, JiaXX, ZhouHY, et al.. Applications of MXenes in wearable sensing: Advances, challenges, and prospects. Mater. Today, 2024, 75359

[18] HuMM, ZhangH, HuT, FanBB, WangXH, LiZJ. Emerging 2D MXenes for supercapacitors: Status, challenges and prospects. Chem. Soc. Rev., 2020, 49186666

[19] GhidiuM, LukatskayaMR, ZhaoMQ, GogotsiY, BarsoumMW. Conductive two-dimensional titanium carbide ‘clay’ with high volumetric capacitance. Nature, 2014, 516752978

[20] Y. Wei, P. Zhang, R.A. Soomro, Q.Z. Zhu, and B. Xu, Advances in the synthesis of 2D MXenes, Adv. Mater., 33(2021), No. 39, art. No. 2103148.

[21] LiDQ, ZhengWH, GaliSM, et al.. MXenes with ordered triatomic-layer borate polyanion terminations. Nat. Mater., 2024, 2381085

[22] DownesM, ShuckCE, LordRW, et al.. M₅X₄: A family of MXenes. ACS Nano, 2023, 171717158

[23] DahlqvistM, BarsoumMW, RosenJ. MAX phases–past, present, and future. Mater. Today, 2024, 721

[24] J.X. Quan, X.P. Jiang, T. Ding, et al., Recent progress in MXene fiber: Materials, fabrication techniques, and potential applications, Chem. Eng. J., 503(2025), art. No. 158320.

[25] P. Zhang, J.P. Li, D.Y. Yang, R.A. Soomro, and B. Xu, Flexible carbon dots-intercalated MXene film electrode with outstanding volumetric performance for supercapacitors, Adv. Funct. Mater., 33(2023), No. 1, art. No. 2209918.

[26] Y.H. Wang, Y.X. Yuan, H.Y. Geng, W.Q. Yang, and X.R. Chen, Boosting ion diffusion kinetics of MXene inks with water-in-salt electrolyte for screen-printed micro-supercapacitors, Adv. Funct. Mater., 34(2024), No. 34, art. No. 2400887.

[27] PanYN, LiH, DuZQ. Electrical/optical dual-energy-driven MXene fabric-based heater with fast response actuating and human strain sensing. J. Mater. Sci. Technol., 2024, 19757

[28] F. E. A. Latif, A. Numan, N.M. Mubarak, et al., Evolution of MXene and its 2D heterostructure in electrochemical sensor applications, Coord. Chem. Rev., 471(2022), art. No. 214755.

[29] NasrinK, SubramaniK, KarnanM, SathishM. MnCo₂S₄–MXene: A novel hybrid electrode material for high performance long-life asymmetric supercapattery. J. Colloid Interface Sci., 2021, 600264

[30] DouQY, WuNZ, YuanHC, et al.. Emerging trends in an-ion storage materials for the capacitive and hybrid energy storage and beyond. Chem. Soc. Rev., 2021, 50126734

[31] S. Panda, K. Deshmukh, S.K. Khadheer Pasha, J. Theerthagiri, S. Manickam, and M.Y. Choi, MXene based emerging materials for supercapacitor applications: Recent advances, challenges, and future perspectives, Coord. Chem. Rev., 462(2022), art. No. 214518.

[32] NaguibM, KurtogluM, PresserV, et al.. Two-dimensional nanocrystals produced by exfoliation of Ti₃AlC₂. Adv. Mater., 2011, 23374248

[33] P.F. Hou, Y.M. Tian, Y. Xie, et al., Unraveling the oxidation behaviors of MXenes in aqueous systems by active-learning-potential molecular-dynamics simulation, Angew. Chem. Int. Ed., 62(2023), No. 32, art. No. e202304205.

[34] O. Mashtalir, M. Naguib, V.N. Mochalin, et al., Intercalation and delamination of layered carbides and carbonitrides, Nat. Commun., 4(2013), art. No. 1716.

[35] XuanJN, WangZQ, ChenYY, et al.. Organic-base-driven intercalation and delamination for the production of functionalized titanium carbide nanosheets with superior photothermal therapeutic performance. Angew. Chem. Int. Ed., 2016, 554714569

[36] N.J. Chen, Z.Y. Duan, W.R. Cai, et al., Supercritical etching method for the large-scale manufacturing of MXenes, Nano Energy, 107(2023), art. No. 108147.

[37] Y.B Wang, B. Zhou, Q. Tang, et al., Ultrafast synthesis of MXenes in minutes via low-temperature molten salt etching, Adv. Mater., 36(2024), No. 49, art. No. 2410736.

[38] NatuV, PaiR, SokolM, CareyM, KalraV, BarsoumMW. 2D Ti₃C₂T_z MXene synthesized by water-free etching of Ti₃AlC₂ in polar organic solvents. Chem, 2020, 63616

[39] X.Q. Bin, Y.P. Tian, Y.Y. Luo, et al., High-performance flexible and free-standing N-doped Ti₃C₂T_x/MoO_x films as electrodes for supercapacitors, Electrochim. Acta, 389(2021), art. No. 138774.

[40] Z.G. Du, C. Wu, Y.C. Chen, et al., High-entropy atomic layers of transition-metal carbides (MXenes), Adv. Mater., 33(2021), No.39, art. No. 2101473.

[41] NemaniSK, ZhangBW, WyattBC, et al.. High-entropy 2D carbide MXenes: TiVNbMoC₃ and TiVCrMoC₃. ACS Nano, 2021, 15812815

[42] X. Tang, X. Guo, W.J. Wu, and G.X. Wang, 2D metal carbides and nitrides (MXenes) as high-performance electrode materials for lithium-based batteries, Adv. Energy Mater., 8(2018), No. 33, art. No. 1801897.

[43] SarychevaA, GogotsiY. Raman spectroscopy analysis of the structure and surface chemistry of Ti₃C₂T_x MXene. Chem. Mater., 2011, 23374248

[44] YangS, ZhangPP, WangFX, et al.. Fluoride-free synthesis of two-dimensional titanium carbide (MXene) using a binary aqueous system. Angew. Chem. Int. Ed., 2018, 574715491

[45] LiTF, YaoLL, LiuQL, et al.. Fluorine-free synthesis of high-purity Ti₃C₂T_x (T = OH, O) via alkali treatment. Angew. Chem. Int. Ed., 2018, 57216115

[46] ZhaoDY, ZhaoRZ, DongSH, et al.. Alkali-induced 3D crinkled porous Ti₃C₂ MXene architectures coupled with Ni-CoP bimetallic phosphide nanoparticles as anodes for highperformance sodium-ion batteries. Energy Environ. Sci., 2019, 1282422

[47] TanHK, SunL, XieF, HuJJ, QuYR, ZhangYH. SnS nanosheets firmly bound in alkali-treated wrinkled MXene framework with enhanced lithium-ion storage. J. Colloid Interface Sci., 2023, 633737

[48] ChenJZ, ChenMF, ZhouWJ, et al.. Simplified synthesis of fluoride-free Ti₃C₂T_x via electrochemical etching toward high-performance electrochemical capacitors. ACS Nano, 2022, 1622461

[49] WangXY, WangZY, QiuJS. Stabilizing MXene by hydration chemistry in aqueous solution. Angew. Chem. Int. Ed., 2021, 605126587

[50] UrbankowskiP, AnasoriB, MakaryanT, et al.. Synthesis of two-dimensional titanium nitride Ti₄N₃ (MXene). Nanoscale, 2016, 82211385

[51] LiM, LuJ, LuoK, et al.. Element replacement approach by reaction with lewis acidic molten salts to synthesize nanolaminated MAX phases and MXenes. J. Am. Chem. Soc., 2019, 141114730

[52] KamysbayevV, FilatovAS, HuHC, et al.. Covalent surface modifications and superconductivity of two-dimensional metal carbide MXenes. Science, 2020, 3696506979

[53] LiYB, ShaoH, LinZF, et al.. A general lewis acidic etching route for preparing MXenes with enhanced electrochemical performance in non-aqueous electrolyte. Nat. Mater., 2020, 198894

[54] WeiSQ, ZhangPJ, XuWJ, et al.. Operando exploring and modulating phase evolution chemistry from MAX to MXenes in molten salt synthesis. J. Am. Chem. Soc., 2023, 1451910681

[55] J.M. Zhu, S.L. Zhu, Z.D. Cui, et al., Solvent-free one-step green synthesis of MXenes by “gas-phase selective etching”, Energy Storage Mater., 70(2024), art. No. 103503.

[56] GogotsiY, AnasoriB. The rise of MXenes. ACS Nano, 2019, 1388491

[57] ZhongJJ, QinL, LiJL, YangZ, YangK, ZhangMJ. MOF-derived molybdenum selenide on Ti₃C₂T_x with superior capacitive performance for lithium-ion capacitors. Int. J. Miner. Metall. Mater., 2022, 2951061

[58] LiuLH, LiN, HanJR, YaoKL, LiangHY. Multicomponent transition metal phosphide for oxygen evolution. Int. J. Miner. Metall. Mater., 2022, 293503

[59] Y.F. Guan, R. Zhao, Y. Cong, et al., Flexible Ti₂C MXene film: Synthesis, electrochemical performance and capacitance behavior, Chem. Eng. J., 433(2022), art. No. 133582.

[60] B. Anasori, M.R. Lukatskaya, and Y. Gogotsi, 2D metal carbides and nitrides (MXenes) for energy storage, Nat. Rev. Mater., 2(2017), art. No. 16098.

[61] GuoK, WangW, JiaoSQ. Recent progress and prospective on layered anode materials for potassium-ion batteries. Int. J. Miner. Metall. Mater., 2022, 2951037

[62] Q. Zhang, B. Gao, L. Zhang, et al., Anomalous water molecular gating from atomic-scale graphene capillaries for precise and ultrafast molecular sieving, Nat. Commun., 14(2023), No. 1, art. No. 6615.

[63] ChenYC, YangHC, HanZJ, et al.. MXene-based electrodes for supercapacitor energy storage. Energy Fuels, 2022, 3652390

[64] LukatskayaMR, MashtalirO, RenCE, et al.. Cation intercalation and high volumetric capacitance of two-dimensional titanium carbide. Science, 2013, 34161531502

[65] ZhangT, MatthewsK, VahidMohammadiA, HanMK, GogotsiY. Pseudocapacitance of vanadium carbide MXenes in basic and acidic aqueous electrolytes. ACS Energy Lett., 2022, 7113864

[66] Y.Y. Xie, G.L. Chen, Y. Tang, et al., Unraveling the ionic storage mechanism of flexible nitrogen-doped MXene films for high-performance aqueous hybrid supercapacitors, Small, 20(2024), No. 51, art. No. 2405817.

[67] Y.P. Tian, M.M. Ju, Y.J. Luo, X.Q. Bin, X.J. Lou, and W.X. Que, In situ oxygen doped Ti₃C₂T_x MXene flexible film as supercapacitor electrode, Chem. Eng. J., 446(2022), art. No. 137451.

[68] RenYY, ZhuJF, WangL, et al.. Synthesis of polyaniline nanoparticles deposited on two-dimensional titanium carbide for high-performance supercapacitors. Mater. Lett., 2018, 21484

[69] LuoYJ, QueWX, TangY, et al.. Regulating functional groups enhances the performance of flexible microporous MXene/bacterial cellulose electrodes in supercapacitors. ACS Nano, 2024, 181811675

[70] LiuZX, TianYP, YangJ, et al.. Ultrafast ion transport in 2D confined MXene for improved electrochemical performance: Boron-atom-substituted-OH termination. ACS Nano, 2024, 184732950

[71] S. Pu, Z.X. Wang, Y.T. Xie, et al., Origin and regulation of self-discharge in MXene supercapacitors, Adv. Funct. Mater., 33(2023), No. 8, art. No. 2208715.

[72] ChenXF, ZhuYZ, ZhangM, et al.. N-Butyllithium-treated Ti₃C₂T_x MXene with excellent pseudocapacitor performance. ACS Nano, 2019, 1389449

[73] ShaoH, XuK, WuYC, et al.. Unraveling the charge storage mechanism of Ti₃C₂T_x MXene electrode in acidic electrolyte. ACS Energy Lett., 2020, 592873

[74] MashtalirO, CookKM, MochalinVN, CroweM, BarsoumMW, GogotsiY. Dye adsorption and decomposition on two-dimensional titanium carbide in aqueous media. J. Mater. Chem. A, 2014, 214334

[75] WangXH, BakSM, HanMK, et al.. Surface redox pseudocapacitance of partially oxidized titanium carbide MXene in water-in-salt electrolyte. ACS Energy Lett., 2022, 7130

[76] Y.H. Wang, C. Ma, W.Q. Ma, et al., Enhanced low-temperature Li-ion storage in MXene titanium carbide by surface oxygen termination, 2D Mater., 6(2019), No. 4, art. No. 045025.

[77] YangL, KanDX, AgneseC D, et al.. Performance improvement of MXene-based perovskite solar cells upon property transition from metallic to semiconductive by oxidation of Ti₃C₂T_x in air. J. Mater. Chem. A, 2021, 95016

[78] LuoJW, JiaC, ShenMH, ZhangSC, ZhuXD. Enhancement of adsorption and energy storage capacity of biomass-based N-doped porous carbon via cyclic carbothermal reduction triggered by nitrogen dopants. Carbon, 2019, 155403

[79] L.Y. Liu, H. Zschiesche, M. Antonietti, et al., Tuning the surface chemistry of MXene to improve energy storage: Example of nitrification by salt melt, Adv. Energy Mater., 13(2023), No. 2, art. No. 2202709.

[80] TianYP, QueWX, LuoYY, YangCH, YinXT, KongLB. Surface nitrogen-modified 2D titanium carbide (MXene) with high energy density for aqueous supercapacitor applications. J. Mater. Chem. A, 2019, 775416

[81] A. Saha, N. Shpigel, Rosy, et al., Enhancing the energy storage capabilities of Ti₃C₂T_x MXene electrodes by atomic surface reduction, Adv. Funct. Mater., 31(2021), No. 52, art. No. 2106294.

[82] S. Li, Q. Shi, Y. Li, et al., Intercalation of metal ions into Ti₃C₂T_x MXene electrodes for high-areal-capacitance microsupercapacitors with neutral multivalent electrolytes, Adv. Funct. Mater., 30(2020), No. 40, art. No. 2003721.

[83] LuoYT, ZhangSQ, PanHY, et al.. Unsaturated single atoms on monolayer transition metal dichalcogenides for ultrafast hydrogen evolution. ACS Nano, 2020, 141767

[84] Z.W. Gao, W.R. Zheng, and L.Y.S. Lee, Highly enhanced pseudocapacitive performance of vanadium-doped MXenes in neutral electrolytes, Small, 15(2019), No. 40, art. No. 1902649.

[85] HanMK, MaleskiK, ShuckCE, et al.. Tailoring electronic and optical properties of MXenes through forming solid solutions. J. Am. Chem. Soc., 2020, 1424519110

[86] AnasoriB, XieY, BeidaghiM, et al.. Two-dimensional, ordered, double transition metals carbides (MXenes). ACS Nano, 2015, 9109507

[87] HantanasirisakulK, AnasoriB, NemsakS, et al.. Evidence of a magnetic transition in atomically thin Cr₂TiC₂T_x MXene. Nanoscale Horiz., 2020, 5121557

[88] L.K. Wang, M.K. Han, C.E. Shuck, X.H. Wang, and Y. Gogotsi, Adjustable electrochemical properties of solid-solution MXenes, Nano Energy, 88(2021), art. No. 106308.

[89] ZhaoJY, YanWZ, LiuZX, LiuXB, TianYP, CuiXW. Optimizing electronic structure of Mo₂TiC₂T_x MXene through Nb doping for enhanced electrochemical performance. Nano Res., 2024, 1787174

[90] CuiYLS, ZhangYZ, CaoZJ, et al.. A perspective on high-entropy two-dimensional materials. SusMat, 2022, 2165

[91] Z.G. Du, C. Wu, Y.C. Chen, et al., High-entropy carbonitride MAX phases and their derivative MXenes, Adv. Energy Mater., 12(2022), No. 6, art. No. 2103228.

[92] ZhouJ, TaoQZ, AhmedB, et al.. High-entropy laminate metal carbide (MAX Phase) and its two-dimensional derivative MXene. Chem. Mater., 2022, 3452098

[93] H.H. Wang, P. Li, J.Y. Ren, et al., Complexation-induced mechanically stiff and reprocessable supramolecular polymeric materials with facile surface patterning, Mater. Today Chem., 42(2024), art. No. 102365.

[94] WuNT, ZhaoZB, ZhangYM, et al.. Revealing the fast reaction kinetics and interfacial behaviors of CuFeS₂ hollow nanorods for durable and high-rate sodium storage. J. Colloid Interface Sci., 2025, 679990

[95] H.Y. Xu, R.X. Zheng, D.Y. Du, et al., Adjusting the 3d orbital occupation of Ti in Ti₃C₂ MXene via nitrogen doping to boost oxygen electrode reactions in Li–O₂ battery, Small, 19(2023), No. 9, art. No. 2206611.

[96] Z.X. Liu, Y.P. Tian, S.Q. Li, et al., Revealing high-rate and high volumetric pseudo-intercalation charge storage from boron-vacancy doped MXenes, Adv. Funct. Mater., 33(2023), No. 40, art. No. 2301994.

[97] W.Z. Bao, L. Liu, C.Y. Wang, S. Choi, D. Wang, and G.X. Wang, Facile synthesis of crumpled nitrogen-doped MXene nanosheets as a new sulfur host for lithium-sulfur batteries, Adv. Energy Mater., 8(2018), No. 13, art. No. 1702485.

[98] ZhouGM, PeiSF, LiL, et al.. A graphene–pure-sulfur sandwich structure for ultrafast, long-life lithium–sulfur batteries. Adv. Mater., 2014, 264625

[99] MathisTS, MaleskiK, GoadA, et al.. Modified MAX phase synthesis for environmentally stable and highly conductive Ti₃C₂ MXene. ACS Nano, 2021, 1546420

[100] SangXH, XieY, LinMW, et al.. Atomic defects in monolayer titanium carbide (Ti₃C₂T_x) MXene. ACS Nano, 2016, 10109193

[101] N.T. Wu, J.K. Shen, X.L. Zhou, et al., Constructing iron vacancies in thiospinel FeIn₂S₄ to modulate Fe D-band center and accelerate sodiation kinetics enabling high-rate and durable sodium storage, Adv. Energy Mater., 15(2025), No. 19, art. No. 2405729.

[102] GanJY, LiFH, TangQ. Vacancies-engineered M₂CO₂ MXene as an efficient hydrogen evolution reaction electrocatalyst. J. Phys. Chem. Lett., 2021, 12204805

[103] YuanWY, ChengLF, AnYR, et al.. MXene nanofibers as highly active catalysts for hydrogen evolution reaction. ACS Sustainable Chem. Eng., 2018, 678976

[104] HanXT, LiNN, XiongPX, et al.. Electronically coupled layered double hydroxide/MXene quantum dot metallic hybrids for high-performance flexible zinc–air batteries. InfoMat, 2021, 3101134

[105] J.M. Yuan, M.B. Gao, Z.Q. Liu, et al., Hyperloop-like diffusion of long-chain molecules under confinement, Nat. Commun., 14(2023), No. 1, art. No. 1735.

[106] P. Chang, H. Mei, Y. Zhao, et al., Nature-inspired 3D spiral grass structured graphene quantum dots/MXene nanohybrids with exceptional photothermal-driven pseudo-capacitance improvement, Adv. Sci., 9(2022), No. 30, art. No. 2204086.

[107] C. Zhang, X.T. Yin, G.J. Qian, Z. Sang, Y.W. Yang, and W.X. Que, Gate voltage adjusting PbS–I quantum-dot-sensitized InGaZnO hybrid phototransistor with high-sensitivity, Adv. Funct. Mater., 34(2024), No. 4, art. No. 2308897.

[108] X.T. Zuo, L.F. Wang, M.M. Zhen, T.T. You, D.P. Liu, and Y. Zhang, Multifunctional TiN–MXene–Co@CNTs networks as sulfur/lithium host for high-areal-capacity lithium-sulfur batteries, Angew. Chem. Int. Ed., 63(2024), No. 35, art. No. e202408026.

[109] WuNT, HeWJ, ShiSC, et al.. Bamboo fiber-derived carbon support for the immobilization of Pt nanoparticles to enhance hydrogen evolution reaction. J. Colloid Interface Sci., 2025, 684658

[110] X. Liang, Y. Rangom, C.Y. Kwok, Q. Pang, and L.F. Nazar, Interwoven MXene nanosheet/carbon-nanotube composites as Li–S cathode hosts, Adv. Mater., 29(2017), No. 3, art. No. 1603040.

[111] S.J. Wan, X. Li, Y. Chen, et al., Ultrastrong MXene films via the synergy of intercalating small flakes and interfacial bridging, Nat. Commun., 13(2022), No. 1, art. No. 7340.

[112] ZhaoMQ, RenCE, LingZ, et al.. Flexible MXene/carbon nanotube composite paper with high volumetric capacitance. Adv. Mater., 2015, 272339

[113] YueY, LiuNS, MaYN, et al.. Highly self-healable 3D microsupercapacitor with MXene-graphene composite aerogel. ACS Nano, 2018, 1254224

[114] Y.B. Wang, N.J. Chen, B. Zhou, et al., NH₃-induced in situ etching strategy derived 3D-interconnected porous MXene/carbon dots films for high performance flexible supercapacitors, Nano micro Lett., 15(2023), No. 1, art. No. 231.

[115] LiL, WuSM, WuK, et al.. Carbon dot-regulated 2D MXene films with high volumetric capacitance. Ind. Eng. Chem. Res., 2020, 593113969

[116] Q.D. Liang, K. Liu, T. Xu, et al., Interfacial modulation of Ti₃C₂T_x MXene by cellulose nanofibrils to construct hybrid fibers with high volumetric specific capacitance, Small, 20(2024), No. 17, art. No. 2307344.

[117] G.Q. Zhou, M.C. Li, C.Z. Liu, Q.L. Wu, and C.T. Mei, 3D printed Ti₃C₂T_x MXene/cellulose nanofiber architectures for solid-state supercapacitors: Ink rheology, 3D printability, and electrochemical performance, Adv. Funct. Mater., 32(2022), No. 14, art. No. 2109593.

[118] L.Y. Zhu, H.B. Yang, T. Xu, L.Y. Wang, J.D. Lei, and C.L. Si, Engineered nanochannels in MXene heterogeneous proton exchange membranes mediated by cellulose nanofiber/sodium alginate dual crosslinked networks, Adv. Funct. Mater., 35(2025), No. 19, art. No. 2419334.

[119] H.L. Zhan, Z.Y. Xiong, C. Cheng, Q.H. Liang, J.Z. Liu, and D. Li, Solvation-involved nanoionics: New opportunities from 2D nanomaterial laminar membranes, Adv. Mater., 32(2020), No. 18, art. No. 1904562.

[120] BandaH, PériéS, DaffosB, et al.. Sparsely pillared graphene materials for high-performance supercapacitors: Improving ion transport and storage capacity. ACS Nano, 2019, 1321443

[121] X.L. Li, N. Li, Z.D. Huang, et al., Enhanced redox kinetics and duration of aqueous I₂/I⁻ conversion chemistry by MXene confinement, Adv. Mater., 33(2021), No. 8, art. No. 2006897.

[122] M. Salanne, B. Rotenberg, K. Naoi, et al., Efficient storage mechanisms for building better supercapacitors, Nat. Energy, 1(2016), art. No. 16070.

[123] BéguinF, PresserV, BalducciA, FrackowiakE. Carbons and electrolytes for advanced supercapacitors. Adv. Mater., 2014, 26142219

[124] MouterdeT, KeerthiA, PoggioliAR, et al.. Molecular streaming and its voltage control in ångström-scale channels. Nature, 2019, 567774687

[125] FornasieroF, ParkHG, HoltJK, et al.. Ion exclusion by sub-2-nm carbon nanotube pores. Proc. Natl. Acad. Sci. USA, 2008, 1054517250

[126] HongS, ConstansC, Surmani MartinsMV, SeowYC, Guevara CarrióJA, GarajS. Scalable graphene-based membranes for ionic sieving with ultrahigh charge selectivity. Nano Lett., 2017, 172728

[127] J.F. He, Y.C. Tang, G.G. Liu, et al., Intrinsic hydrogen-bond donors-lined organophosphate superionic nanochannels levering high-rate-endurable aqueous Zn batteries, Adv. Energy Mater., 12(2022), No. 46, art. No. 2202661.

[128] J. Tang, T. Mathis, X.W. Zhong, et al., Optimizing ion pathway in titanium carbide MXene for practical high-rate supercapacitor, Adv. Energy Mater., 11(2021), No. 4, art. No. 2003025.

[129] WangXH, MathisTS, LiK, et al.. Influences from solvents on charge storage in titanium carbide MXenes. Nat. Energy, 2019, 43241

[130] XuN, QianT, LiuXJ, LiuJ, ChenY, YanCL. Greatly suppressed shuttle effect for improved lithium sulfur battery performance through short chain intermediates. Nano Lett., 2017, 171538

[131] K. Liang, R.A. Matsumoto, W. Zhao, et al., Engineering the interlayer spacing by pre-intercalation for high performance supercapacitor MXene electrodes in room temperature ionic liquid (adv. funct. mater. 33/2021), Adv. Funct. Mater., 31(2021), No. 33, art. No. 2170246.

[132] YangC, WuX, XiaHY, et al.. 3D printed template-assisted assembly of additive-free Ti₃C₂T_x MXene microlattices with customized structures toward high areal capacitance. ACS Nano, 2022, 1622699

[133] K. Li, J. Zhao, A. Zhussupbekova, et al., 4D printing of MXene hydrogels for high-efficiency pseudocapacitive energy storage, Nat. Commun., 13(2022), No. 1, art. No. 6884.

[134] M.J. Wang, Y.F. Cheng, H.Y. Zhang, et al., Nature-inspired interconnected macro/meso/micro-porous MXene electrode, Adv. Funct. Mater., 33(2023), No. 12, art. No. 2211199.

[135] M.R. Lukatskaya, S. Kota, Z.F. Lin, et al., Ultra-high-rate pseudocapacitive energy storage in two-dimensional transition metal carbides, Nat. Energy, 2(2017), art. No. 17105.

[136] P. Zhang, Y.M. Peng, Q.Z. Zhu, R.A. Soomro, N. Sun, and B. Xu, 3D foam-based MXene architectures: Structural and electrolytic engineering for advanced potassium-ion storage, Energy Environ. Mater., 7(2024), No. 4, art. No. e12379.

[137] P. Zhang, Q.Z. Zhu, R.A. Soomro, et al., In situ ice template approach to fabricate 3D flexible MXene film-based electrode for high performance supercapacitors, Adv. Funct. Mater., 30(2020), No. 47, art. No. 2000922.

[138] XuHJ, FanJX, SuH, et al.. Metal ion-induced porous MXene for all-solid-state flexible supercapacitors. Nano Lett., 2023, 231283

[139] H.W. Chen, H.P. Wang, and C. Li, Mechanically induced nanoscale architecture endows a titanium carbide MXene electrode with integrated high areal and volumetric capacitance, Adv. Mater., 34(2022), No. 43, art. No. 2205723.

[140] P.L. Ji, L. Liu, Y. Deng, et al., Three-dimensional hierarchical porous MXene aerogel with outstanding rate performance for flexible supercapacitors, J. Energy Storage, 93(2024), art. No. 112194.

[141] J.Y. Dong, L. Hua, Z.Q. Lu, et al., Double cross-linking system for constructing tortuosity-lowered and strength-enhanced porous MXene films with superior capacitive performance and electromagnetic shielding efficiency, Energy Storage Mater., 72(2024), art. No. 103686.

[142] LiZN, GadipelliS, LiHC, et al.. Tuning the interlayer spacing of graphene laminate films for efficient pore utilization towards compact capacitive energy storage. Nat. Energy, 2020, 52160

[143] J.M. Zhu, S.L. Zhu, Z.D. Cui, et al., Dual redox reaction sites for pseudocapacitance based on Ti and –P functional groups of Ti₃C₂PBr_x MXene, Angew. Chem. Int. Ed., 63(2024), No. 27, art. No. e202403508.

[144] X.C. Wei, M. Cai, F.L. Yuan, et al., The surface functional modification of Ti₃C₂T_x MXene by phosphorus doping and its application in quasi-solid state flexible supercapacitor, Appl. Surf. Sci., 606(2022), art. No. 154817.

[145] XiaoZM, SunKS, ZhengY, et al.. Implementation of high-capacity 3D Ti₃C₂T_X MXene supercapacitors with terminal group modification. ACS Appl. Mater. Interfaces, 2023, 154451151

[146] X.W. Hu, N. Gong, Q.C. Zhang, et al., N-terminalized Ti₃C₂T_x MXene for supercapacitor with extraordinary pseudocapacitance performance, Small, 20(2024), No. 8, art. No. 2306997.

[147] F.L. Yang, D. Hegh, D.X. Song, et al., Synthesis of nitrogensulfur Co-doped Ti₃C₂T_x MXene with enhanced electrochemical properties, Mater. Rep. Energy, 2(2022), No. 1, art. No. 100079.

[148] D. Lu, Y.W. Lu, Y.F. Liang, et al., The phosphorus doping modification of Ti₃C₂T_x MXene films assisted by tripolyphosphate-crosslinking for flexible supercapacitors, J. Energy Storage, 100(2024), art. No. 113524.

[149] WenYY, LiR, LiuJH, et al.. A temperature-dependent phosphorus doping on Ti₃C₂T_x MXene for enhanced supercapacitance. J. Colloid Interface Sci., 2021, 604239

[150] P.C. Sun, J.Y. Liu, Q. Liu, et al., Nitrogen and sulfur Co-doped MXene ink without additive for high-performance inkjet-printing micro-supercapacitors, Chem. Eng. J., 450(2022), art. No. 138372.

[151] W.W. Liu, D. Luo, M.W. Zhang, et al., Engineered MXene quantum dots for micro-supercapacitors with excellent capacitive behaviors, Nano Energy, 122(2024), art. No. 109332.

[152] Y.H. Xue, S.F. Chao, M. Xu, et al., Multi-layers hexagonal hole MXene trap constructed by carbon vacancy defect regulation strategy enables high energy density potassium-ions storage, Energy Storage Mater., 71(2024), art. No. 103558.

[153] C.J. Shi, Z.J. Liu, Z. Tian, et al., Regulated layer spacing and functional surface group of MXene film by hexamethylenetetramine for high-performance supercapacitors, Appl. Surf. Sci., 596(2022), art. No. 153632.

[154] WangHF, WangYR, ChangJ, et al.. Nacre-inspired strong MXene/cellulose fiber with superior supercapacitive performance via synergizing the interfacial bonding and interlayer spacing. Nano Lett., 2023, 23125663

[155] W.M. Chen, D.T. Zhang, K. Yang, M. Luo, P. Yang, and X.Y. Zhou, Mxene (Ti₃C₂T_x)/cellulose nanofiber/porous carbon film as free-standing electrode for ultrathin and flexible supercapacitors, Chem. Eng. J., 413(2021), art. No. 127524.

[156] ZhuC, GengFX. Macroscopic MXene ribbon with oriented sheet stacking for high-performance flexible supercapacitors. Carbon Energy, 2021, 31142

[157] R.J. Zhang, J.D. Dong, W. Zhang, et al., Synergistically coupling of 3D FeNi–LDH arrays with Ti₃C₂T_x–MXene nanosheets toward superior symmetric supercapacitor, Nano Energy, 91(2022), art. No. 106633.

[158] ZhuGY, HouYN, LuJQ, et al.. MXene decorated 3D-printed carbon black-based electrodes for solid-state micro-supercapacitors. J. Mater. Chem. A, 2023, 114625422

[159] Z.X. Zhu, Z.X. Wang, Z.H. Ba, et al., 3D MXene-holey graphene hydrogel for supercapacitor with superior energy storage, J. Energy Storage, 47(2022), art. No. 103911.

[160] WangXY, FuQS, WenJ, et al.. 3D Ti₃C₂T_x aerogels with enhanced surface area for high performance supercapacitors. Nanoscale, 2018, 104420828

RIGHTS & PERMISSIONS

University of Science and Technology Beijing