Enhancing Oxygen Reduction Activity and Cr Tolerance of Solid Oxide Fuel Cell Cathodes by a Multiphase Catalyst Coating

Intermediate temperature solid oxide fuel cells (IT-SOFCs) are cost-effective and efficient energy conversion systems. The sluggish oxygen reduction reaction (ORR) and the degradation of cathodes are critical challenges to the commercialization of IT-SOFCs. Here, a highly efficient multiphase (MP) catalyst coating, consisting of Ba_1−xCo_0.7Fe_0.2Nb_0.1O_3−δ (BCFN) and BaCO₃, to enhance the ORR activity and durability of the state-of-the-art lanthanum strontium cobalt ferrite (La_0.6Sr_0.4Co_0.2Fe_0.8O_3−δ, LSCF) cathode is reported. The conformal MP catalyst-coated LSCF cathode shows a polarization resistance (R_p) of 0.048 Ω cm² at 650 °C, about one order of magnitude smaller than that of the bare LSCF. In an accelerated Cr-poisoning test, the degradation rate of the catalyst-coated LSCF electrode is 10⁻³ Ω cm² h⁻¹ (0.59% h⁻¹) over 200 h, only one fifth of the degradation rate of the bare LSCF electrode at 750 °C. In addition, anode-supported single cells with the MP catalyst-coated LSCF cathode show a dramatically enhanced peak power density (1.4 W cm⁻² vs 0.67 W cm⁻² at 750 °C) and increased durability against Cr and H₂O. Both experimental results and density functional theory-based calculations indicate that the BCFN phase improves the ORR activity while the BaCO₃ phase enhances the stability of the LSCF cathode.     

Interlayer Injection of Low-Valence Zn Atoms to Activate MXene-Based Micro-Redox Capacitors With Battery-Type Voltage Plateaus

Insufficient and unstable energy output is the bottleneck issue radically restricting the application of micro-supercapacitors (MSCs). Herein, an interlayer atom injection strategy that can anchor low-valence Zn atoms (Zn^δ+, 0 < δ <2) on O-terminals of Ti₃C₂T_x (MXene) flakes within the MXene/silver-nanowires hybrid cathode of symmetric MSCs is first presented. Combining the polyacrylamide/ZnCl₂ hydrogel electrolyte rich in Cl⁻ and Zn²⁺ ions, the matched Zn^δ+/Zn²⁺ (−0.76 V vs SHE) and Ag/AgCl (0.23 V vs SHE), redox couples between the symmetrical electrodes are activated to offer faradaic charge storage beside ions-intercalation involved pseudocapacitance. Thus, a battery-type voltage plateau (≈0.9 V) appears in the discharge curve of a fabricated pseudo-symmetric micro-redox capacitor, simultaneously achieving energy density enhancement (117 µWh cm⁻² at 0.5 mA cm⁻²) and substantially improved power output stability (46% of the energy from the plateau region) relative to that before activation (98 µWh cm⁻² without voltage platform). The work provides a fire-new strategy to overcome the performance bottlenecks confronting conventional MSCs.     

High-Performance Flow Alkali-Al/Acid Hybrid Fuel Cell for High-Rate H2 Generation

Hydrogen (H₂) has been utilized as a versatile feedstock or promising energy carrier in a variety of fields, yet the implementation of high-rate H₂ production presents a grand challenge for its readily accessible application. Herein, a newly alkali-Al/acid hybrid fuel cell (3AHFC) that shows the capability of rapidly producing H₂ upon delivering a considerably high energy density is reported, which is set up by paring Al anode in alkaline anolyte with acidic catholyte and a relatively cheap nanohybrid of Ru nanoparticle decorating crumpled reduced graphene oxide (Ru/c-rGO) as cathode catalysts. It is demonstrated that the 3AHFC can release a power density of up to 240.6 mW cm⁻² with a Faradic efficiency of approaching 99% for fast H₂ generation (300 mA cm⁻²). Such hybrid electrolyte H₂-generation fuel cell can also be extended for either seawater anolyte or metallic Mg anode, presenting great promise for the practice feasibility of on-site H₂ production for applications in tough or even extreme environments.     

Bifunctional Hydrated Gel Electrolyte for Long-Cycling Zn-Ion Battery with NASICON-Type Cathode

Aqueous Zn-ion batteries are promising and safe energy storage technologies. However, current aqueous electrolyte Zn-ion battery technology is hindered by undesirable reactions between the electrolyte and electrodes, which can lead to Zn dendrite growth, gas evolution, and cathode degradation. In this study, a hydrated gel electrolyte (HGE) that combines adiponitrile (ADN) and Zn(ClO₄)₂·6H₂O in a polymeric framework is created. ADN is found to stabilize the interface between the electrolyte and anode/cathode, enabling smooth Zn stripping/plating and reducing parasitic reactions. The HGE is simple to fabricate, inexpensive, safe, and flexible. Zn/HGE/Zn symmetrical cells can cycle more than 1000 h at 0.5 mA cm⁻² and 2000 h at 0.2 mA cm⁻² without short-circuiting, indicating effective suppression of Zn dendrites. Moreover, with a NASICON-type Sr-doped Na₃V₂(PO₄)₃ (SNVP) cathode, a Zn/HGE/SNVP full cell can be cycled over 8000 times at 10 C while retaining a high capacity of 90 mAh g⁻¹.     

A Shape-Variable,Low-Temperature Liquid Metal–Conductive Polymer Aqueous Secondary Battery

A shape-variable aqueous secondary battery operating at low temperature is developed using Ga₆₈In₂₂Sn₁₀ (wt%) as a liquid metal anode and a conductive polymer (polyaniline (PANI)) cathode. In the GaInSn alloy anode, Ga is the active component, while Sn and In increase the acid resistance and decrease the eutectic point to -19 °C. This enables the use of strongly acidic aqueous electrolytes (here, pH 0.9), thereby improving the activity and stability of the PANI cathode. Consequently, the battery exhibits excellent electrochemical performance and mechanical stability. The GaInSn–PANI battery operates via a hybrid mechanism of Ga³⁺ stripping/plating and Cl⁻ insertion/extraction and delivers a high reversible capacity of over 223.9 mAh g⁻¹ and an 80.3% retention rate at 0.2 A g⁻¹ after 500 cycles, as well as outstanding power and energy densities of 4300 mW g⁻¹ and 98.7 mWh g⁻¹, respectively. Because of the liquid anode, the battery without packaging can be deformed with a small force of several millinewtons without any capacity loss. Moreover, at approximately -5 °C, the battery delivers a capacity of 67.8 mAh g⁻¹ at 0.2 A g⁻¹ with 100% elasticity. Thus, the battery is promising as a deformable energy device at low temperatures and in demanding environments.     

In Situ Engineering of a Cobalt-free Perovskite Air Electrode Enabling Efficient Reversible Oxygen Reduction/Evolution Reactions

Reversible protonic ceramic electrochemical cells (R-PCECs) have received increasing focus for their good capability of converting and storing energy. However, the widely used cobalt-based air electrodes are less thermomechanically compatible with the electrolyte and lack stability, which largely limits the development of R-PCECs. Herein, a cobalt-free perovskite with a nominal composition of PrBa_0.8Ca_0.2Fe_1.8Ce_0.2O_6δ (PBCFC) is reported, which is in–situ engineered to a (Ba, Ce) deficient-PBCFC phase, a BaCeO₃, and a CeO₂ phase under typical operating conditions, delivering a low area–specific resistance of 0.10 Ωcm² at 700 ^oC. The generated BaCeO₃ and CeO₂ particles increase the conduction/transfer of protons and oxygen ions, thus providing extra active sites for the oxygen reactions. When utilized as an air electrode on a single cell, it achieves encouraging performance at 700 °C: a peak power density of 1.78 Wcm⁻² and a current density of 5.00 Acm⁻² at 1.3 V in the dual mode of the fuel cell (FC) and electrolysis (EL) mode with reasonable Faradaic efficiencies. In addition, the cells exhibit favorable operational durability of 65 h (FC mode), 95 h (EL mode), and promising cycling stability of 200 h.     

The Synergistic Activation of Ce-Doping and CoP/Ni3P Hybrid Interaction for Efficient Water Splitting at Large-Current-Density

The high intermediate (H*, OH*) energy barriers and slow mass/charge transfer increase the overpotential of alkaline water electrolysis at large-current-density. Engineering the electronic structure with the morphology of the catalyst to reduce energy barriers and improve mass/charge transportation is effective but remains challenging. Herein, a Ce-doped CoP nanosheet is hybrid with Ni₃P@NF (Ni foam) support to enhance mass/charge transfer, tune energy barriers, and improve water-splitting kinetics through a synergistic activation. The engineered Ce_0.2-CoP/Ni₃P@NF cathode exhibits an ultralow overpotential (η₅₀₀, η₁₀₀₀) of −185, and −225 mV at −500 and −1000 mA cm⁻² in 1.0 m  KOH, along with an excellent pH-universality. Impressively, an electrolyzer using the Ce_0.2-CoP/Ni₃P@NF cathode can afford 500 mA cm⁻² at a cell voltage of only 1.775 V and maintain stable electrolysis for 200 h in 25 wt% KOH (50 °C). Characterization and density functional theory calculation further reveal the Ce-doping and CoP/Ni₃P hybrid interaction synergistically downshift d-band centers (ε_d = −2.0 eV) of Ce_0.2-CoP/Ni₃P to the Fermi level, thereby activate local electronic structure for accelerating H₂O dissociation and optimizing Gibbs free energy of hydrogen adsorption (∆G_H*).     

Metallic Particles-Induced Surface Reconstruction Enabling Highly Durable Zinc Metal Anode

Aqueous zinc batteries usher in a renaissance due to their intrinsic security and cost effectiveness, bespeaking vast application foreground for large-scale energy storage system. However, uncontrolled dendrite growth along with hydrogen evolution severely restricts its reversibility and stability for practical application. Herein, the surface of Zn metal is reconstructed with metallic particles (In, Sn, In_0.2Sn_0.8) to diminish surface defects and regulate Zn deposition behavior. The alloyed In–Sn greatly activates the Zn surface for lower Zn adsorption energy barrier to expedite plating kinetics and confine Zn aggregation. Dense and uniform deposition of Zn on the reconstructed surface significantly prevents the Zn substrate from dendrites growth for catastrophic damage. Meanwhile, alloy layer embodies high hydrogen evolution overpotential, ensuring high plating and stripping efficiency for Zn anode. Consequently, In_0.2Sn_0.8 reconstructed surface realizes long-term lifespan up to 1800 h with low polarization (12 mV) at the condition of 1 mA cm⁻² and 1 mAh cm⁻². When paired with sodium vanadate (NVO) cathode, the full cell steady operates for a high-capacity retention of 94.0% after 5000 cycles at 5 A g⁻¹. This study provides new insights into the surface-defects dependent Zn deposition process and offers a guide for constructing stable surface for dendrite-free Zn growth.     

A Low-Cost,Durable Bifunctional Electrocatalyst Containing Atomic Co and Pt Species for Flow Alkali-Al/Acid Hybrid Fuel Cell and Zn–Air Battery

Transition metal single atoms anchored on nitrogen-doped carbon (M-N-C) matrix with M-N-C active sites have shown to be promising catalysts for both hydrogen evolution reaction (HER) and oxygen reduction reaction (ORR). Herein, a hybrid catalyst with low-level loading of atomic Pt and Co species encapsulated in nitrogen-doped graphene (Pt@CoN₄-G) is developed. The Pt@CoN₄-G shows low overpotential for HER in wide-pH electrolyte and manifests improved mass activity with almost eight times greater than that of Pt/C at an overpotential of 50 mV. The Pt@CoN₄-G also exhibits a top-level ORR activity (half-wave potential, E_1/2 = 0.893 V) and robust stability (>200 h) in alkaline medium. Using theoretical calculations and comprehensive characterizations , the strong metal–support interactions between Pt species and CoN₄-G support and synergistical cooperation of multiple active sites are clarified. A flow alkali-Al/acid hybrid fuel cell using Pt@CoN₄-G as cathode catalyst delivers a large power density of 222 mW cm⁻² with excellent stability to achieve simultaneously hydrogen evolution and electricity generation. In addition, Pt@CoN₄-G endows a flow Zn-air battery with high power density (316 mW cm⁻²), good stability under large current density (>100 h at 100 mA cm⁻²), and long cycle life (over 600 h at 5 mA cm⁻²).     

Stabilizing the Interphase in Cobalt-Free,Ultrahigh-Nickel Cathodes for Lithium-Ion Batteries

High-nickel layered oxide cathodes, such as LiNi_1-x-yMn_xCo_yO₂ (NMC) and LiNi_1-x-yCo_xAl_yO₂ (NCA), are at the forefront for implementation in high-energy-density lithium-ion batteries. The presence of cobalt in both cathode chemistries, however, largely deters their application due to fiscal and humanitarian issues affiliated with cobalt sourcing. Increasing the Ni content drives down the Co content, but introduces additional structural and electrochemical problems attributed to high-Ni cathodes. Herein a dually modified cobalt-free ultrahigh-nickel cathode 0.02B-LiNi_0.99Mg_0.01O₂ (NBM) is presented with 1 mol% Mg and 2 mol% B that exhibits a high initial 1C discharge capacity of 210 mA h g⁻¹ with a 20% capacity retention improvement over 500 cycles when benchmarked against LiNiO₂ (LNO) in pouch full cell configurations with graphite anode. Postmortem analyses reveal the enhanced performance stems from reduced active lithium inventory loss and localized surface reactivity in the NBM cathode. The stabilized cathode-electrolyte interphase subsequently reduces transition-metal dissolution and ensuing chemical crossover to the graphite anode, which prevents further catalyzed parasitic reactions that harmfully passivate the anode surface. Altogether, this study aims to highlight the importance of electrode characterization and analysis from an interphasial viewpoint and to push the ongoing research to stabilize cobalt-free ultrahigh-Ni cathodes for industrial feasibility.     

Porphyrin Aerogel Catalysts for Oxygen Reduction Reaction in Anion-Exchange Membrane Fuel Cells

Platinum group metal (PGM)-free catalysts for oxygen reduction reaction have shown high oxygen reduction reaction activity in alkaline media. In order to further increase the power density of anion-exchange membrane fuel cells (AEMFCs), PGM-free catalysts need to have a high site density to reach high current densities. Herein, synthesis, characterization, and utilization of heat-treated iron porphyrin aerogels are reported as cathode catalysts in AEMFCs. The heat treatment effect is thoroughly studied and characterized using several techniques, and the best performing aerogel is studied in AEMFC, showing excellent performance, reaching a peak power density of 580 mW cm⁻² and a limiting current density of as high as 2.0 A cm⁻², which can be considered the state-of-the-art for PGM-free based AEMFCs.     

Natural Hematite for Next‐Generation Solid Oxide Fuel Cells

Natural hematite ore is used as a novel electrolyte material for advanced solid oxide fuel cells (SOFCs). This hematite‐based system exhibits a maximum power density of 225 mW cm^?2 at 600 °C and reaches 467 mW cm^?2 when the hematite is mixed with perovskite‐structured La_0.6Sr_0.4Co_0.2Fe_0.8O_3–δ. These results demonstrate that natural materials for next‐generation SOFCs can influence the multiutilization of natural resources, thereby affecting the environment and energy sustainability.     

Hollow Molybdate Microspheres as Catalytic Hosts for Enhancing the Electrochemical Performance of Sulfur Cathode under High Sulfur Loading and Lean Electrolyte

Lithium–sulfur battery possesses a high energy density; however, its application is severely blocked by several bottlenecks, including the serious shuttling behavior and sluggish redox kinetics of sulfur cathode, especially under the condition of high sulfur loading and lean electrolyte. Herein, hollow molybdate (CoMoO₄, NiMoO₄, and MnMoO₄) microspheres are introduced as catalytic hosts to address these issues. The molybdates present a high intrinsic electrocatalytic activity for the conversion of soluble lithium polysulfides, and the unique hollow spherical structure could provide abundant sites and spatial confinement for electrocatalysis and inhibiting shuttling, respectively. Meanwhile, it is demonstrated that the unique adsorption of molybdates toward polysulfides exhibits a “volcano-type” feature with the catalytic performance following the Sabatier principle. The NiMoO₄ hollow microspheres with moderate adsorption show the highest electrocatalytic activity, which is favorable for enhancing the electrochemical performance of sulfur cathode. Especially, the S/NiMoO₄ composite could achieve a high areal capacity of 7.41 mAh cm⁻² (906.2 mAh g⁻¹) under high sulfur loading (8.18 mg cm⁻²) and low electrolyte/sulfur ratio (E/S, 4 µL mg⁻¹). This work offers a new perspective on searching accurate rules for selecting and designing effective host materials in the lithium–sulfur battery.     

High-Performance Garnet-Type Solid-State Lithium Metal Batteries Enabled by Scalable Elastic and Li+-Conducting Interlayer

Promoting the interfacial Li⁺ transport and suppressing detrimental lithium dendrites are the main challenges for developing practical solid-state lithium metal batteries. In this respect, interface rationalizing to synergize the enhancement of ion transport and suppression of lithium dendrites is of paramount significance. Herein, a novel strategy is demonstrated to address those issues by a designed multifunctional composite interlayer. The photocrosslinkable polymer is introduced in a scalable elastic skeleton, which promotes the migration and diffusion of Li⁺. Moreover, adding perfluoropolyether in the interlayer benefits to regulating the formation of LiF-rich interface, sufficiently suppress the growth of lithium dendrites. Benefitting from the elasticity, high Li⁺ conductivity and the lithium dendrites suppression capability, the interlayer can significantly improve the interfacial performance of the solid electrolyte/lithium interface, thus leading to the greatly enhanced electrochemical performance of solid-state lithium metal batteries. A high critical current density of 3.6 mA cm⁻² and a long cycling life at 1.0 mA cm⁻² for >400 h are achieved for the symmetric cells. Besides, when used in a pouch-type full cell coupled with LiNi_0.6Co_0.2Mn_0.2O₂ cathode, a high charged capacity of 3.25 mAh cm⁻² can be maintained through 20 cycles, demonstrating its great potentials for practical application.     

Constructing Electronic and Ionic Dual Conductive Polymeric Interface in the Cathode for High-Energy-Density Solid-State Batteries

Solid–solid interfaces in the composite cathode for solid-state batteries face the thorny issues of poor physical contact, chemical side reaction, temporal separation, and sluggish Li⁺/e⁻ transfer. Developing key material to achieve the composite cathode with efficient solid–solid interfaces is critical to improving the coulombic efficiency, cycling life, and energy density of solid-state batteries. Herein, electronic and ionic dual conductive polymer (DCP) is prepared for the composite cathode via intermolecular interaction on the base of lithiated polyvinyl formal-derived Li⁺ single-ion conductor (LiPVFM), lithium difluoro(oxalato)borate (LiODFB), and electronic conducting polymer. Crosslinking, coordination, and hydrogen-bonding effect enable DCP with high electrical conductivity of 68.9 S cm⁻¹, Li⁺ ionic conductivity (2.76 × 10⁻⁴ S cm⁻¹), large electrochemical window above 6 V and a high modulus of 6.8 GPa. Besides, DCP can form a coating layer on the active material powders to maintain structural integrity via buffering the internal stress during lithiation/delithiation, meanwhile, to construct long- and short-range electronic/ionic conductive channel together with a small amount of CNTs. Rigid and flexible DCP-based composite cathode enables the excellent cycling of solid-state batteries with a high loading up to 11.7 mg cm⁻² and high content of active materials close to 90 wt% without current collector.     

Optimized Cathode for High-Energy Sodium-Ion Based Dual-Ion Full Battery with Fast Kinetics

The most used systems based on the graphite-based cathode show unsatisfactory performance in dual-ion batteries. Developing new type cathode materials with high capacity for new type anions storage is an effective way to improve the total performance of dual-ion batteries. Herein, a protonated polyaniline (P-PANI) cathode is prepared to realize efficient and stable storage of ClO₄^–, and a high reversible capacity of 143 mAh g⁻¹ at 0.2 A g⁻¹ after 200 cycles can be obtained, which is competitive compared with common graphite cathodes. In addition, the highly reversible coordination storage mechanism between ClO₄⁻ and P-PANI cathode is indicated, rather than the labored intercalation reactions between PF₆⁻ and graphite. Subsequently, a full cell (P-PANI//N-PDHC) fabricated with a P-PANI cathode and hard carbon anode (N-PDHC) can deliver a high energy density of 284 Wh kg^–1 for 2000 cycles at 2 A g^–1, and the relevant pouch-type full cell can easily power a smartphone. In general, this work may promote the exploitation of sodium-based dual-ion batteries in practical application.     

Enabling High-Performance NASICON-Based Solid-State Lithium Metal Batteries Towards Practical Conditions

Solid-state lithium metal batteries (SSLMBs) are promising next-generation high-energy rechargeable batteries. However, the practical energy densities of the reported SSLMBs have been significantly overstated due to the use of thick solid-state electrolytes, thick lithium (Li) anodes, and thin cathodes. Here, a high-performance NASICON-based SSLMB using a thin (60 µm) Li_1.5Al_0.5Ge_1.5(PO₄)₃ (LAGP) electrolyte, ultrathin (36 µm) Li metal, and high-loading (8 mg cm⁻²) LiFePO₄ (LFP) cathode is reported. The thin and dense LAGP electrolyte prepared by hot-pressing exhibits a high Li ionic conductivity of 1 × 10⁻³ S cm⁻¹ at 80 °C. The assembled SSLMB can thus deliver an increased areal capacity of ≈1 mAh cm⁻² at C/5 with a high capacity retention of ≈96% after 50 cycles under 80 °C. Furthermore, it is revealed by synchrotron X-ray absorption spectroscopy and in situ high-energy X-ray diffraction that the side reactions between LAGP electrolyte and LFP cathode are significantly suppressed, while rational surface protection is required for Ni-rich layered cathodes. This study provides valuable insights and guidelines for the development of high-energy SSLMBs towards practical conditions.     

Cross-Doped Mn/Mo Oxides with Core-Shell Structures Designed by a Self-Template Strategy for Durable Aqueous Zinc-Ion Batteries

Manganese oxide as the star cathode material of aqueous zinc ion batteries is vigorously developed because of its environmental protection, outstanding theoretical capacity, and high voltage. However, severe Jahn–Teller distortion of trivalent Mn has detrimental effect on cyclic stability. Herein, 1D core-shell bimetal oxide with cross-doping of heteroatom is successfully designed by self-template method via one-step hydrothermal reaction. Specifically, the thick shell of Mo-doped α-MnO₂ with increased nanopores, expanded lattice spacing, and high oxidation state not only contributes high capacity but also suppresses the lattice distortion due to the doping of high-valent Mo⁶⁺; While the thin core of Mn-doped MoO₃ nanobelt supplies a shaped template, important Mo source, and improved conductive path. Therefore, this composite exhibits a superior capacity of 366.2 mAh g⁻¹ at 0.2 A g⁻¹ and 100% capacity retention after 100 cycles, which effectively increases to 4.1 times from 1.5 times of pure α-MnO₂ based battery. Besides promoting the electrochemical performance in coin-cell batteries, composite materials also balance the electrochemical and mechanical performances in flexible micro-batteries with area energy density of 261.2 µWh cm⁻². Therefore, this synergetic self-template and cross-doping strategy can extend to the material design of other high-performance metal oxides for energy storage application.     

Flexible Solid-State Direct Ethanol Fuel Cell Catalyzed by Nanoporous High-Entropy Al-Pd-Ni-Cu-Mo Anode and Spinel (AlMnCo)3O4 Cathode

As in many other electrochemical energy-converting systems, the flexible direct ethanol fuel cells rely heavily on high-performance catalysts with low noble metal contents and high tolerance to poisoning. In this work, a generic dealloying procedure to synthesize nanoporous multicomponent anodic and cathodic catalysts for the high-performance ethanol fuel cells is reported. On the anode side, the nanoporous AlPdNiCuMo high-entropy alloy exhibits an electrochemically active surface area of 88.53 m² g⁻¹_Pd and a mass activity of 2.67 A mg⁻¹_Pd for the ethanol oxidation reaction. On the cathode side, the dealloyed spinel (AlMnCo)₃O₄ nanosheets with no noble metals demonstrate a comparable catalytic performance as the standard Pt/C for the oxygen reduction reaction, and tolerance to high concentrations of ethanol. Equipped with such anodic and cathodic catalysts, the flexible solid-state ethanol fuel cell is able to deliver an ultra-high energy density of 13.63 mWh cm⁻² with only 3 mL ethanol, which is outstanding compared with other similar solid-state energy devices. Moreover, the solid-state ethanol fuel cell is highly flexible, durable and exhibits an inject-and-run function.     

Toward Stable Cycling of a Cost-Effective Cation-Disordered Rocksalt Cathode via Fluorination

The recently developed Li-excess cation-disordered rock salts (DRXs) exhibit an excellent chemical diversity for the development of alternative Co/Ni-free high-energy cathodes. Herein, the synthesis of a highly fluorinated DRX cathode, Li_1.2Mn_0.6Ti_0.2O_1.8F_0.2, based on cost-effective and earth-abundant transition metals, via a solid-state reaction, is reported. The fluorinated DRX cathode using ammonium fluoride precursor exhibits more uniform particle size and delivers a specific discharge capacity of 233 mAh g⁻¹ and specific energy of 754 Wh kg⁻¹, with 206 mAh g⁻¹ retained after 200 cycles. The combined synchrotron X-ray absorption spectroscopy and resonant inelastic X-ray scattering spectroscopy analysis reveals that the remarkable cycling performance is attributed to the high fluorination and thus enhanced Mn content, enabling the utilization of more Mn redox than the oxide analog. This study demonstrates a great promise to develop next-generation cost-effective DRX cathodes with enhanced capacity retention for high-energy Li-ion batteries.