钠离子电池锰基层状氧化物正极材料的阴离子氧化还原反应调控研究

正极材料容量低是限制钠离子电池商业化应用的瓶颈之一。基于阴离子氧化还原反应（Anionic Redox Reaction，ARR）的锰基层状氧化物（Na_xA_yMn_1−yO₂，A代表Ni²⁺和Mg²⁺等），因其容量高和成本低等优点，是最具发展潜力的高能钠离子电池正极材料。然而该类正极材料存在ARR不稳定性引起的晶格氧释放，以及Mn³⁺的Jahn−Teller效应引起晶格畸变及扭曲等问题，最终导致其动力学缓慢、电压滞后和电压衰减。因此，本论文通过元素掺杂策略以稳定材料的结构以及调控晶格氧的局域环境，从而提高Na_xA_yMn_1−yO₂的ARR可逆性，实现稳定的循环性能。

首先，针对P2−Na_0.67Ni_0.33Mn_0.67O₂面临高压结构畸变、多次有序重排和不可逆ARR过程等问题，本文深入研究了Li掺杂对P2−Na_0.67Li_xNi_0.33−xMn_0.67O₂结构和性能的影响。通过多种原位表征手段，证明Li取代部分Ni能够有效抑制有害晶格畸变以及Na⁺/空位有序排布，提升ARR可逆性。改性后的材料表现出“低应变”（仅1.2%的晶格体积变化）和单相固溶体反应特性。在1C下比容量达到109.2 mAh g⁻¹，循环200次后仍然具有80.1%的高容量保持率。

然后，选择阴离子氧化还原反应更剧烈的Na_0.6Mg_0.23Mn_0.77O₂正极材料为研究对象，提出Li和Cu共掺杂策略来调控其电子结构分布和晶体结构框架，并深入研究了其结构特性和储钠机制。研究表明，低价态Li⁺和强共价性Cu²⁺共掺杂能够有效抑制了晶格结构的扭曲和畸变，减缓了晶格氧释放以及Mn溶解，减少了表面裂纹的形成，这有助于提高ARR可逆性和缓解电压滞后、电压衰减和容量衰减等问题。在0.1C的倍率下比容量达到207.3 mAh g⁻¹，循环50次后容量保持率高达80.5%。

本论文的研究成果充分证实了低价态Li⁺有效抑制脱嵌Na⁺过程中的堆叠层错及结构畸变；具有强共价性Cu²⁺能够与O形成牢固的Cu−O键进而抑制晶格氧释放，以此有效提升Na_xA_yMn_1−yO₂的ARR可逆性和循环稳定性。研究成果为设计高性能的钠离子电池正极材料提供了新思路。

Low capacity of the cathode materials remain one of the bottlenecks limiting the commercialization of sodium-ion batteries (SIBs). Due to high capacity and low cost, layered manganese oxides based on anionic redox reactions (ARR), such as Na_xA_yMn_1−yO₂ where A represents Ni²⁺ and Mg²⁺, are considered the most promising high-energy SIB cathode materials. However, these cathode materials suffer from issues such as lattice oxygen release caused by unstable ARR and lattice distortion and twisting induced by the Jahn−Teller effect of Mn³⁺, leading to slow kinetics, voltage hysteresis, and voltage decay. Therefore, this study proposes the element doping strategy to stabilize the structure of material and regulate the local environment of lattice oxygen, aiming to enhance the reversibility of ARR in Na_xA_yMn_1−yO₂ and achieving stable cycling performance.

Firstly, addressing the issues of structural distortion, Na⁺/vacancy  ordering, and irreversible ARR processes in P2-Na_0.67Ni_0.33Mn_0.67O₂, the effects of Li doping on the structure and performance of P2-Na_0.67Li_xNi_0.33−xMn_0.67O₂ were thoroughly investigated. Through various in-situ characterizations, it was demonstrated that partial substitution of Ni with Li effectively suppressed harmful lattice distortion and Na⁺/vacancy ordering, enhancing the reversibility of ARR and suppressing lattice oxygen release. Therefore, the modified material exhibited "low strain" (only 1.2% lattice volume change) and single-phase solid solution reaction characteristics. Moreover, the material achieved a specific capacity of 109.2 mAh g⁻¹ at 1C and maintained a high capacity retention rate of 80.1% after 200 cycles.

The Na_0.6Mg_0.23Mn_0.77O₂ positive electrode material, which shows higher capacity but more intense ARR, was further investigated. A Li and Cu co-doping strategy was conducted to regulate its electronic structure distribution and crystal structure framework, and the structural characteristics and storage mechanism of Na⁺ were further explored. The results showed that co-doping with low-valence Li⁺ and strong-covalent Cu²⁺ effectively inhibited lattice distortion and twisting, mitigated lattice oxygen release and Mn dissolution and reduced surface crack formation, thereby improving the reversibility of ARR and alleviating issues such as voltage hysteresis, voltage decay, and capacity decay. A specific capacity of 207.3 mAh g⁻¹ was achieved at a rate of 0.1C, and the capacity retention rate remained as high as 80.5% after 50 cycles.

The research findings of this study strongly confirm that the presence of low-valent Li⁺ effectively suppresses the stacking faults and structural distortions during the sodiation/desodiation process. Moreover, the strong covalent nature of Cu²⁺ facilitates the formation of robust Cu−O bonds, thereby inhibiting lattice oxygen release. Consequently, this approach significantly enhances the reversibility of ARR process and the cycling stability of Na_xA_yMn_1−yO₂. These results provide novel insights for the design of high-performance sodium-ion battery cathode materials.

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[1] ZHAO H, YUAN Z Y. Progress and Perspectives for Solar-Driven Water Electrolysis to Produce Green Hydrogen[J]. Advanced Energy Materials, 2023, 13(16): 2300254.

[2] RASTGAR M, MORADI K, BURROUGHS C, et al. Harvesting Blue Energy Based on Salinity and Temperature Gradient: Challenges, Solutions, and Opportunities[J]. Chemical Reviews, 2023, 123(16): 10156-10205.

[3] ZHANG H, GAO Y, LIU X, et al. Long-Cycle-Life Cathode Materials for Sodium-Ion Batteries toward Large-Scale Energy Storage Systems[J]. Advanced Energy Materials, 2023, 13(23): 2300149.

[4] REN J-T, CHEN L, WANG H-Y, et al. Water electrolysis for hydrogen production: from hybrid systems to self-powered/catalyzed devices[J]. Energy & Environmental Science, 2024, 17(1): 49-113.

[5] HUANG Y, LI J. Key Challenges for Grid-Scale Lithium-Ion Battery Energy Storage[J]. Advanced Energy Materials, 2022, 12(48): 2202197.

[6] GOURLEY S W D, BROWN R, ADAMS B D, et al. Zinc-ion batteries for stationary energy storage[J]. Joule, 2023, 7(7): 1415-1436.

[7] LIU Y, CUI X, CAO Y, et al. Low-Cost H2/Na0.44MnO2 Gas Battery for Large-Scale Energy Storage[J]. ACS Energy Letters, 2023, 8(8): 3639-3645.

[8] YANG W, YANG Y, YANG H, et al. Regulating Water Activity for Rechargeable Zinc-Ion Batteries: Progress and Perspective[J]. ACS Energy Letters, 2022, 7(8): 2515-2530.

[9] FENG Y, ZHOU L, MA H, et al. Challenges and advances in wide-temperature rechargeable lithium batteries[J]. Energy & Environmental Science, 2022, 15(5): 1711-1759.

[10] ZHU Z, JIANG T, ALI M, et al. Rechargeable Batteries for Grid Scale Energy Storage[J]. Chemical Reviews, 2022, 122(22): 16610-16751.

[11] OLIVETTI E A, CEDER G, GAUSTAD G G, et al. Lithium-Ion Battery Supply Chain Considerations: Analysis of Potential Bottlenecks in Critical Metals[J]. Joule, 2017, 1(2): 229-243.

[12] MUñOZ M Á, SAUREL D, GóMEZ J L, et al. Na-Ion Batteries for Large Scale Applications: A Review on Anode Materials and Solid Electrolyte Interphase Formation[J]. Advanced Energy Materials, 2017, 7(20): 1700463.

[13] CHAYAMBUKA K, MULDER G, DANILOV D L, et al. From Li-Ion Batteries toward Na-Ion Chemistries: Challenges and Opportunities[J]. Advanced Energy Materials, 2020, 10(38).

[14] LARCHER D, TARASCON J M. Towards greener and more sustainable batteries for electrical energy storage[J]. Nature Chemistry, 2014, 7(1): 19-29.

[15] HAO Z, SHI X, YANG Z, et al. The Distance Between Phosphate-Based Polyanionic Compounds and Their Practical Application For Sodium-Ion Batteries[J]. Advanced Materials, 2023, 36(7): 2305135.

[16] GRITZNER G. Standard electrode potentials of M+|M couples in non-aqueous solvents (molecular liquids)[J]. Journal of Molecular Liquids, 2010, 156(1): 103-108.

[17] DENG J, LUO W B, CHOU S L, et al. Sodium-Ion Batteries: From Academic Research to Practical Commercialization[J]. Advanced Energy Materials, 2017, 8(4): 1701428.

[18] Experimental and computational advancement of cathode materials for futuristic sodium ion batteries[J]. Materials Today, 2023, DOI: 10.1016/j.mattod.2023.06.0137.

[19] PAN H, HU Y-S, CHEN L. Room-temperature stationary sodium-ion batteries for large-scale electric energy storage[J]. Energy & Environmental Science, 2013, 6(8): 2338-2360.

[20] C. Delmas, C. Fouassier , P. Hagenmuller. Structural classification and properties of the layered oxides[J]. Physica B+C, 1980, 99(1-4): 81-85.

[21] B. G. SILBERNAGEL, WHITTINGHAM M S. The physical properties of the NaxTiS2 intercalation compounds: A synthetic and NMR study[J]. Materials Research Bulletin, 1976, 11: 29-36.

[22]D. A. Stevens1, J. R. Dahn. High Capacity Anode Materials for Rechargeable Sodium-Ion Batteries[J]. Journal of The Electrochemical Society, 2000, 147(4): 1271-1273.

[23] YABUUCHI N, HARA R, KAJIYAMA M, et al. New O2/P2-type Li-Excess Layered Manganese Oxides as Promising Multi-Functional Electrode Materials for Rechargeable Li/Na Batteries[J]. Advanced Energy Materials, 2014, 4(13): 1301453.

[24] HAN M H, GONZALO E, SINGH G, et al. A comprehensive review of sodium layered oxides: powerful cathodes for Na-ion batteries[J]. Energy & Environmental Science, 2015, 8(1): 81-102.

[25] OH S-M, MYUNG S-T, HASSOUN J, et al. Reversible NaFePO4 electrode for sodium secondary batteries[J]. Electrochemistry Communications, 2012, 22: 149-152.

[26] KIM H, PARK I, SEO D H, et al. New iron-based mixed-polyanion cathodes for lithium and sodium rechargeable batteries: combined first principles calculations and experimental study[J]. Journal of the American Chemical Society, 2012, 134(25): 10369-10372.

[27] CHEN C-Y, MATSUMOTO K, NOHIRA T, et al. Pyrophosphate Na2FeP2O7 as a low-cost and high-performance positive electrode material for sodium secondary batteries utilizing an inorganic ionic liquid[J]. Journal of Power Sources, 2014, 246: 783-787.

[28] WANG L, LU Y, LIU J, et al. A Superior Low-Cost Cathode for a Na-Ion Battery[J]. Angewandte Chemie International Edition, 2013, 52(7): 1964-1967.

[29] LEE H-W, WANG R Y, PASTA M, et al. Manganese hexacyanomanganate open framework as a high-capacity positive electrode material for sodium-ion batteries[J]. Nature Communications, 2014, 5(1): 5280.

[30] YOU Y, WU X-L, YIN Y-X, et al. High-quality Prussian blue crystals as superior cathode materials for room-temperature sodium-ion batteries[J]. Energy & Environmental Science, 2014, 7(5): 1643-1647.

[31] LI Y, YANG Z, XU S, et al. Air-Stable Copper-Based P2-Na7/9Cu2/9Fe1/9Mn2/3O2 as a New Positive Electrode Material for Sodium-Ion Batteries[J]. Advanced Science, 2-015, 2(6): 1500031.

[32] MU L, XU S, LI Y, et al. Prototype Sodium-Ion Batteries Using an Air-Stable and Co/Ni-Free O3-Layered Metal Oxide Cathode[J]. Advanced Materials, 2015, 27(43): 6928-6933.

[33] XU S-Y, WU X-Y, LI Y-M, et al. Novel copper redox-based cathode materials for room-temperature sodium-ion batteries[J]. Chinese Physics B, 2014, 23(11): 118202.

[34] GAO Y, ZHANG H, PENG J, et al. A 30-year overview of sodium-ion batteries[J]. Carbon Energy, 2024, DOI: doi.org/10.1002/cey2.464.

[35] ZUO W, XIAO Z, ZARRABEITIA M, et al. Guidelines for Air-Stable Lithium/Sodium Layered Oxide Cathodes[J]. ACS Materials Letters, 2022, 4(6): 1074-1086.

[36] LI X, LIANG L, SU M, et al. Multi-Level Modifications Enabling Chemomechanically Stable Ni-Rich O3-Layered Cathode toward Wide-Temperature-Tolerance Quasi-Solid-State Na-Ion Batteries[J]. Advanced Energy Materials, 2023, 13(9): 2203701.

[37] SONG T, WANG C, KANG L, et al. P3-Na0.45Ni0.2Mn0.8O2/Na2SeO4 Heterostructure Enabling Long-Life and High-Rate Sodium-Ion Batteries[J]. Advanced Energy Materials, 2023, 13(42): 2302393.

[38] JO J H, KIM H J, CHOI J U, et al. Facilitating sustainable oxygen-redox chemistry for P3-type cathode materials for sodium-ion batteries[J]. Energy Storage Materials, 2022, 46: 329-343.

[39] CAO X, SUN J, CHANG Z, et al. Enabling Long-Term Cycling Stability Within Layered Li-Rich Cathode Materials by O2/O3-Type Biphasic Design Strategy[J]. Advanced Functional Materials, 2022, 32(39): 2205199.

[40] LIU Y F, HAN K, PENG D N, et al. Layered oxide cathodes for sodium-ion batteries: From air stability, interface chemistry to phase transition[J]. InfoMat, 2023, 5(6).

[41] GREY C P, TARASCON J M. Sustainability and in situ monitoring in battery development[J]. Nature Materials, 2016, 16(1): 45-56.

[42] CAI T, CAI M, MU J, et al. High-Entropy Layered Oxide Cathode Enabling High-Rate for Solid-State Sodium-Ion Batteries[J]. Nano-Micro Letters, 2023, 16(1): 10.

[43] WANG Y, ZHAO X, JIN J, et al. Boosting the Reversibility and Kinetics of Anionic Redox Chemistry in Sodium-Ion Oxide Cathodes via Reductive Coupling Mechanism[J]. Journal of the American Chemical Society, 2023, 145(41): 22708-22719.

[44] GONZALO E, ZARRABEITIA M, DREWETT N E, et al. Sodium manganese-rich layered oxides: Potential candidates as positive electrode for Sodium-ion batteries[J]. Energy Storage Materials, 2021, 34: 682-707.

[45] J. Parant, C. Fouassier, P. Hagenmuller, et al. Sur quelques nouvelles phases de formule NaxMnO2 (x ⩽ 1)[J]. Journal of Solid State Chemistry, 1971, 3(1): 1-11.

[46] MA X, CHEN H, CEDER G. Electrochemical Properties of Monoclinic NaMnO2[J]. Journal of The Electrochemical Society, 2011, 158(12): A1307-A1312.

[47] BILLAUD J, CLEMENT R J, ARMSTRONG A R, et al. beta-NaMnO2: a high-performance cathode for sodium-ion batteries[J]. Journal of the American Chemical Society, 2014, 136(49): 17243-17248.

[48] CHEN X, WANG Y, WIADEREK K, et al. Super Charge Separation and High Voltage Phase in NaxMnO2[J]. Advanced Functional Materials, 2018, 28(50): 1805105.

[49] LIU S, WAN J, OU M, et al. Regulating Na Occupation in P2-Type Layered Oxide Cathode for All-Climate Sodium-Ion Batteries[J]. Advanced Energy Materials, 2023, 13(11): 2203521.

[50] YABUUCHI N, KUBOTA K, DAHBI M, et al. Research Development on Sodium-Ion Batteries[J]. Chemical Reviews, 2014, 114(23): 11636-11682.

[51] CLAUDE D, CLAUDE F , PAUL H , et al. Influence de l'environnement de l'ion alcalin sur sa mobilite dans les structures a feuillets Ax(LxM1−x)O2[J]. Materials Research Bulletin, 1979, 14(3): 329-335.

[52] ROGER M, MORRIS D J P, TENNANT D A, et al. Patterning of sodium ions and the control of electrons in sodium cobaltate[J]. Nature, 2007, 445(7128): 631-634.

[53] LUONG H D, DINH V A, MOMIDA H, et al. Insight into the diffusion mechanism of sodium ion-polaron complexes in orthorhombic P2 layered cathode oxide NaxMnO2[J]. Phys Chem Chem Phys, 2020, 22(32): 18219-18228.

[54] WANG Q C, SHADIKE Z, LI X L, et al. Tuning Sodium Occupancy Sites in P2-Layered Cathode Material for Enhancing Electrochemical Performance[J]. Advanced Energy Materials, 2021, 11(13).

[55] YAO H-R, LV W-J, YUAN X-G, et al. New insights to build Na+/vacancy disordering for high-performance P2-type layered oxide cathodes[J]. Nano Energy, 2022, 97: 107207.

[56] KUMAKURA S, TAHARA Y, KUBOTA K, et al. Sodium and Manganese Stoichiometry of P2-Type Na2/3MnO2[J]. Angewandte Chemie International Edition, 2016, 55(41): 12760-12763.

[57] LIU X, ZUO W, ZHENG B, et al. P2-Na0.67AlxMn1-xO2: Cost-Effective, Stable and High-Rate Sodium Electrodes by Suppressing Phase Transitions and Enhancing Sodium Cation Mobility[J]. Angewandte Chemie International Edition, 2019, 58(50): 18086-18095.

[58] GAO X, CHEN J, LIU H, et al. Copper-substituted NaxMO2 (M=Fe, Mn) cathodes for sodium ion batteries: Enhanced cycling stability through suppression of Mn(III) formation[J]. Chemical Engineering Journal, 2021, 406.

[59] LIU H, GAO X, CHEN J, et al. Cu-substitution P2-Na0.66Mn1-xCuxO2 sodium-ion cathode with enhanced interlayer stability[J]. Journal of Energy Chemistry, 2022, 75: 478-485.

[60] ZUO W, QIU J, LIU X, et al. Highly-stable P2-Na0.67MnO2 electrode enabled by lattice tailoring and surface engineering[J]. Energy Storage Materials, 2020, 26: 503-512.

[61] JIANG H, QIAN G, LIU R, et al. Effects of elemental doping on phase transitions of manganese-based layered oxides for sodium-ion batteries[J]. Science China Materials, 2023, 66(12): 4542-4549.

[62] WANG C, LIU L, ZHAO S, et al. Tuning local chemistry of P2 layered-oxide cathode for high energy and long cycles of sodium-ion battery[J]. Nature Communications, 2021, 12(1): 2256.

[63] MA C, ALVARADO J, XU J, et al. Exploring Oxygen Activity in the High Energy P2-Type Na0.78Ni0.23Mn0.69O2 Cathode Material for Na-Ion Batteries[J]. Journal of the American Chemical Society, 2017, 139(13): 4835-4845.

[64] WANG P F, YOU Y, YIN Y X, et al. Suppressing the P2-O2 Phase Transition of Na0.67Mn0.67Ni0.33O2 by Magnesium Substitution for Improved Sodium-Ion Batteries[J]. Angewandte Chemie International Edition, 2016, 55(26): 7445-7449.

[65] ZUO W, REN F, LI Q, et al. Insights of the anionic redox in P2–Na0.67Ni0.33Mn0.67O2[J]. Nano Energy, 2020, 78: 105285.

[66] CHENG Z, ZHAO B, GUO Y J, et al. Mitigating the Large-Volume Phase Transition of P2-Type Cathodes by Synergetic Effect of Multiple Ions for Improved Sodium-Ion Batteries[J]. Advanced Energy Materials, 2022, 12(14): 2103461.

[67] ROUXEL J. Anion–Cation Redox Competition and the Formation of New Compounds in Highly Covalent Systems[J]. Chemistry – A European Journal, 2006, 2(9): 1053-1059.

[68] SUN L, WU Z, HOU M, et al. Unraveling and suppressing the voltage decay of high-capacity cathode materials for sodium-ion batteries[J]. Energy & Environmental Science, 2024, 17(1): 210-218.

[69] SEO D H, LEE J, URBAN A, et al. The structural and chemical origin of the oxygen redox activity in layered and cation-disordered Li-excess cathode materials[J]. Nature Chemistry, 2016, 8(7): 692-697.

[70] LAI Y, XIE H, LI P, et al. Ion-Migration Mechanism: An Overall Understanding of Anionic Redox Activity in Metal Oxide Cathodes of Li/Na-Ion Batteries[J]. Advanced Materials, 2022, 34(47): 2206039.

[71] OKUBO M, YAMADA A. Molecular Orbital Principles of Oxygen-Redox Battery Electrodes[J]. ACS Applied Materials & Interfaces, 2017, 9(42): 36463-36472.

[72] ZAANEN J, SAWATZKY G A, ALLEN J W. Band gaps and electronic structure of transition-metal compounds[J]. Physical Review Letters, 1985, 55(4): 418-421.

[73] ASSAT G, TARASCON J-M. Fundamental understanding and practical challenges of anionic redox activity in Li-ion batteries[J]. Nature Energy, 2018, 3(5): 373-386.

[74] LI F, LIU R, LIU J, et al. Voltage Hysteresis in Transition Metal Oxide Cathodes for Li/Na-Ion Batteries[J]. Advanced Functional Materials, 2023, 33(28): 2300602.

[75] ZUO W, YANG Y. Synthesis, Structure, Electrochemical Mechanisms, and Atmospheric Stability of Mn-Based Layered Oxide Cathodes for Sodium Ion Batteries[J]. Accounts of Materials Research, 2022, 3(7): 709-720.

[76] HOUSE R A, MAITRA U, PéREZ-OSORIO M A, et al. Superstructure control of first-cycle voltage hysteresis in oxygen-redox cathodes[J]. Nature, 2019, 577(7791): 502-508.

[77] BOIVIN E, HOUSE R A, PéREZ-OSORIO M A, et al. Bulk O2 formation and Mg displacement explain O-redox in Na0.67Mn0.72Mg0.28O2[J]. Joule, 2021, 5(5): 1267-1280.

[78] EUM D, KIM B, SONG J-H, et al. Coupling structural evolution and oxygen-redox electrochemistry in layered transition metal oxides[J]. Nature Materials, 2022, 21(6): 664-672.

[79] WANG P-F, YOU Y, YIN Y-X, et al. An O3-type NaNi0.5Mn0.5O2cathode for sodium-ion batteries with improved rate performance and cycling stability[J]. Journal of Materials Chemistry A, 2016, 4(45): 17660-17664.

[80] 赵成龙. 钠离子电池层状氧化物电极材料的合成设计与性能研究[D].中国科学院大学(中国科学院物理研究所), 2015.

[81] CUI Z, MANTHIRAM A. Thermal Stability and Outgassing Behaviors of High‐nickel Cathodes in Lithium-ion Batteries[J]. Angewandte Chemie International Edition, 2023, 62(43): e202307243.

[82] KIM E J, MA L A, DUDA L C, et al. Oxygen Redox Activity through a Reductive Coupling Mechanism in the P3-Type Nickel-Doped Sodium Manganese Oxide[J]. ACS Applied Energy Materials, 2019, 3(1): 184-191.

[83] CHENG C, LI S, LIU T, et al. Elucidation of Anionic and Cationic Redox Reactions in a Prototype Sodium-Layered Oxide Cathode[J]. ACS Applied Materials & Interfaces, 2019, 11(44): 41304-41312.

[84] XIA X, LIU T, CHENG C, et al. Suppressing the Dynamic Oxygen Evolution of Sodium Layered Cathodes through Synergistic Surface Dielectric Polarization and Bulk Site-Selective Co-Doping[J]. Advance Materials, 2023, 35(8): e2209556.

[85] SHEN Q, LIU Y, ZHAO X, et al. Transition-Metal Vacancy Manufacturing and Sodium‐Site Doping Enable a High-Performance Layered Oxide Cathode through Cationic and Anionic Redox Chemistry[J]. Advanced Functional Materials, 2021, 31(51): 2106923.

[86] SHEN Q, LIU Y, ZHAO X, et al. Unexpectedly High Cycling Stability Induced by a High Charge Cut-Off Voltage of Layered Sodium Oxide Cathodes[J]. Advanced Energy Materials, 2022, 13(6): 2203216.

[87] CHENG C, HU H, YUAN C, et al. Precisely modulating the structural stability and redox potential of sodium layered cathodes through the synergetic effect of co-doping strategy[J]. Energy Storage Materials, 2022, 52: 10-18.

[88] SHI Y, LI S, GAO A, et al. Probing the Structural Transition Kinetics and Charge Compensation of the P2-Na0.78Al0.05Ni0.33Mn0.60O2 Cathode for Sodium Ion Batteries[J]. ACS Applied Materials & Interfaces, 2019, 11(27): 24122-24131.

[89] JIN J, LIU Y, SHEN Q, et al. Unveiling the Complementary Manganese and Oxygen Redox Chemistry for Stabilizing the Sodium-Ion Storage Behaviors of Layered Oxide Cathodes[J]. Advanced Functional Materials, 2022, 32(29): 2203424.

[90] LEE D H, XU J, MENG Y S. An advanced cathode for Na-ion batteries with high rate and excellent structural stability[J]. Phys Chem Chem Phys, 2013, 15(9): 3304-3312.

[91] CAI C, LI X, HU P, et al. Comprehensively Strengthened Metal-Oxygen Bonds for Reversible Anionic Redox Reaction[J]. Advanced Functional Materials, 2023, 33(24): 2215155.

[92] XU X, HU S, PAN Q, et al. Enhancing Structure Stability by Mg/Cr Co-Doped for High-Voltage Sodium-Ion Batteries[J]. Small, 2023, 20(12): e2307377.

[93] ZHONG X-B, HE C, GAO F, et al. In situ Raman spectroscopy reveals the mechanism of titanium substitution in P2–Na2/3Ni1/3Mn2/3O2: Cathode materials for sodium batteries[J]. Journal of Energy Chemistry, 2021, 53: 323-328.

[94] PENG B, SUN Z, ZHAO L, et al. Dual-Manipulation on P2-Na0.67Ni0.33Mn0.67O2 Layered Cathode toward Sodium-Ion Full Cell with Record Operating Voltage Beyond 3.5 V[J]. Energy Storage Materials, 2021, 35: 620-629.

[95] JIN J, LIU Y, PANG X, et al. A comprehensive understanding of the anionic redox chemistry in layered oxide cathodes for sodium-ion batteries[J]. Science China Chemistry, 2020, 64(3): 385-402.

[96] XU H, GUO S, ZHOU H. Review on anionic redox in sodium-ion batteries[J]. Journal of Materials Chemistry A, 2019, 7(41): 23662-23678.

[97] SINGH P, DIXIT M. Opportunities and Challenges in the Development of Layered Positive Electrode Materials for High-Energy Sodium Ion Batteries: A Computational Perspective[J]. Langmuir, 2023, 39(1): 28-36.

[98] BASSEY E N, REEVES P J, JONES M A, et al. Structural Origins of Voltage Hysteresis in the Na-Ion Cathode P2–Na0.67[Mg0.28Mn0.72]O2: A Combined Spectroscopic and Density Functional Theory Study[J]. Chemistry of Materials, 2021, 33(13): 4890-4906.

[99] HUANG Y, ZHU Y, NIE A, et al. Enabling Anionic Redox Stability of P2-Na5/6Li1/4Mn3/4O2 by Mg Substitution[J]. Advance Materials, 2022, 34(9): e2105404.

[100]RONG X, XIAO D, LI Q, et al. Boosting reversible anionic redox reaction with Li/Cu dual honeycomb centers[J]. eScience, 2023, 3(5): 100159.

[101]KIM H-J, VORONINA N, KöSTER K, et al. Synergetic impact of dual substitution on anionic–Cationic activity of P2-type sodium manganese oxide[J]. Energy Storage Materials, 2024, 66.

[102]JIN J, LIU Y, ZHAO X, et al. Annealing in Argon Universally Upgrades the Na-Storage Performance of Mn-Based Layered Oxide Cathodes by Creating Bulk Oxygen Vacancies[J]. Angew Chem Int Ed Engl, 2023, 62(15): e202219230.

[103]FU F, LIU X, FU X, et al. Entropy and crystal-facet modulation of P2-type layered cathodes for long-lasting sodium-based batteries[J]. Nature Communications, 2022, 13(1): 2826.

[104]JI H, JI W, XUE H, et al. Synergistic activation of anionic redox via cosubstitution to construct high-capacity layered oxide cathode materials for sodium-ion batteries[J]. Science Bulletin, 2023, 68(1): 65-76.

[105]SAXENA S, BADOLE M, VASAVAN H N, et al. Deciphering the role of optimal P2/O3 phase fraction in enhanced cyclability and specific capacity of layered oxide cathodes[J]. Chemical Engineering Journal, 2024, 485(1): 149921.

[106]KIM B, SONG J-H, EUM D, et al. A theoretical framework for oxygen redox chemistry for sustainable batteries[J]. Nature Sustainability, 2022, 5(8): 708-716.

[107]ZHAO C, YAO Z, WANG J, et al. Ti Substitution Facilitating Oxygen Oxidation in Na2/3Mg1/3Ti1/6Mn1/2O2 Cathode[J]. Chem, 2019, 5(11): 2913-2925.

[108]CAO X, LI X, QIAO Y, et al. Restraining Oxygen Loss and Suppressing Structural Distortion in a Newly Ti-Substituted Layered Oxide P2-Na0.66Li0.22Ti0.15Mn0.63O2[J]. ACS Energy Letters, 2019, 4(10): 2409-2417.

[109]CAO M-H, LI R-Y, LIN S-Y, et al. Oxygen redox chemistry in P2-Na0.6Li0.11Fe0.27Mn0.62O2 cathode for high-energy Na-ion batteries[J]. Journal of Materials Chemistry A, 2021, 9(48): 27651-27659.

[110]TAPIA-RUIZ N, SOARES C, SOMERVILLE J W, et al. P2-Na2/3Mg1/4Mn7/12Co1/6O2 cathode material based on oxygen redox activity with improved first-cycle voltage hysteresis[J]. Journal of Power Sources, 2021, 506: 230104.

[111]LIU J, QI R, ZUO C, et al. Inherent inhibition of oxygen loss by regulating superstructural motifs in anionic redox cathodes[J]. Nano Energy, 2021, 88: 106252.

[112]CHEN C, ZHAO C, LIU H, et al. Mitigating the Formation of Tetrahedral Zn in Layered Oxides Enables Reversible Lattice Oxygen Redox Triggering by the Na–O–Zn Configuration[J]. ACS Nano, 2023, 17(12): 11406-11413.

[113]LU H, CHU S, TIAN J, et al. Ultra-High-Energy Density in Layered Sodium-Ion Battery Cathodes through Balancing Lattice-Oxygen Activity and Reversibility[J]. Advanced Functional Materials, 2023, 34(2): 2305470.

[114]YOON G H, KOO S, PARK S J, et al. Enabling Stable and Nonhysteretic Oxygen Redox Capacity in Li-Excess Na Layered Oxides[J]. Advanced Energy Materials, 2022, 12(11): 2103384.

[115]CAO X, LI H, QIAO Y, et al. Triggering and Stabilizing Oxygen Redox Chemistry in Layered Li[Na1/3Ru2/3]O2 Enabled by Stable Li–O–Na Configuration[J]. ACS Energy Letters, 2022, 7(7): 2349-2356.

[116]HOUSE R A, MAITRA U, JIN L, et al. What Triggers Oxygen Loss in Oxygen Redox Cathode Materials?[J]. Chemistry of Materials, 2019, 31(9): 3293-3300.

[117]LIU S, WANG B, ZHANG X, et al. Reviving the lithium-manganese-based layered oxide cathodes for lithium-ion batteries[J]. Matter, 2021, 4(5): 1511-1527.

[118]WANG P-F, JIN T, ZHANG J, et al. Elucidation of the Jahn-Teller effect in a pair of sodium isomer[J]. Nano Energy, 2020, 77: 105167.

[119]JIN J, LIU Y, ZHAO X, et al. Annealing in Argon Universally Upgrades the Na-Storage Performance of Mn-Based Layered Oxide Cathodes by Creating Bulk Oxygen Vacancies[J]. Angewandte Chemie International Edition, 2023, 62(15): e202219230.

[120]WAN G, DOU W, ZHU H, et al. Empowering higher energy sodium-ion battery cathode by oxygen chemistry[J]. Interdisciplinary Materials, 2023, 2(3): 416-422.

[121]ZHANG Y, HU A, XIA D, et al. Operando characterization and regulation of metal dissolution and redeposition dynamics near battery electrode surface[J]. Nature Nanotechnol, 2023, 18(7): 790-797.

[122]LI X, XU J, LI H, et al. Synergetic Anion-Cation Redox Ensures a Highly Stable Layered Cathode for Sodium-Ion Batteries[J]. Advance Science, 2022, 9(16): e2105280.