Lattice defect regulation on lattice strain and electrochemical kinetics of O3-type NaNi1/3Fe1/3Mn1/3O2 cathode materials for sodium-ion batteries

Improvement of red mud oxygen carriers in biomass chemical looping gasification using battery cathode materials doping

Cobalt-modified catalyst derived from cold-rolled sludge for phenol degradation via PMS-activated fenton-like reaction: Performance and mechanistic investigation.

Abstract Sodium manganese fluorophosphate (Na2MnPO4F), as a novel phosphate-based cathode material, has attracted widespread attention in the scientific community in recent years due to its advantages of high theoretical specific capacity, low cost, and environmental friendliness. However, this material has problems such as poor electronic conductivity and obvious capacity fading during cycling, which limit its practical application. Transition metal cation doping and carbon coating modification are common and effective strategies to improve the electrochemical performance of phosphate-based materials. In this study, Na2MnPO4F/C composites and Na2Mn0.98M0.02PO4F/C composites (where M = Fe2+, Co2+, Ni2+) were synthesized through a wet ball milling and in situ pyrolytic carbon coating process to explore the impact of transition metal cation doping on the structural and electrochemical properties of Na2MnPO4F as a cathode material for lithium-ion batteries. The phase constituents, morphological structure, and electrochemical characteristics of the as-obtained materials were examined using various characterization techniques. The results indicate that the introduction of a small amount of transition metal cations does not alter the crystal structure of Na2MnPO4F; all samples maintain a well-crystallized monoclinic phase (P21/n space group). The samples exhibit a micro-scale aggregate architecture with varying degrees of aggregation, composed of primary nanoparticles measuring approximately 10 to 50 nm. When utilized as cathode materials in lithium-ion batteries, the electrochemical performances of the metal ion-doped Na2MnPO4F/C composites is enhanced compared to the undoped variant. Notably, Na2Mn0.98Ni0.02PO4F/C demonstrates the best comprehensive electrochemical performance, achieving a high initial specific discharge capacity of 116.9 mAh∙g-1 with no significant capacity decay observed after 50 cycles at a charge/discharge current density of 10 mA∙g-1 within a voltage range of 1.5 V to 4.8 V.

Magnesium-based batteries, particularly magnesium-lithium hybrid batteries, have emerged as a promising avenue for next-generation high-performance energy storage technologies, owing to the low cost and high safety of magnesium resources, as well as the rapid kinetic properties of lithium ions. However, the relatively low operating voltage of magnesium-lithium hybrid batteries has limited their widespread application. To address this limitation, this work develops a MoO3nanosheet cathode, which demonstrates a high operating voltage of 1.62 V during discharge and exhibits minimal charge-discharge polarization. Furthermore, at a current density of 50 mA g-1, the battery delivers a high discharge capacity of 163.2 mAh g-1, with a capacity retention of 71.6% after 500 cycles. By integrating the ex-situ characterizations with the first-principles calculations, we demonstrate that MoO3in the magnesium-lithium hybrid system operates via a dual-cation synergistic storage mechanism, in which Li+plays the dominant role while Mg2+participates reversibly. These results indicate that MoO3nanosheets are promising as high-voltage, low-polarization cathode materials for magnesium-lithium hybrid batteries, offering both a viable materials platform and a sound mechanistic foundation for the development of high-performance magnesium-lithium hybrid energy-storage systems.

P'2-type manganese-based layered oxides (NaxMnO2, 0.5 < x < 0.8 usually) have emerged as promising cathode materials for sodium-ion batteries (SIBs), primarily due to their ability to deliver higher capacity compared to P2-type layered oxides. However, the underlying mechanism behind this high capacity still remains unclear, and the cycling stability has been a challenge. Given that distinct Na+ occupation environments (edge-shared Nae and face-shared Naf) in P-type cathodes have different electrochemical kinetics, this study establishes a direct correlation between the high capacity of the P'2 structure and the high Nae/Naf ratio. The theoretical simulation confirms that the P'2 structure can accommodate more Na+ at the Nae site, which features a lower migration energy barrier and enhanced migration. Guided by this insight, a dual-approach rational design─combining quenching treatment and Ti/Fe codoping─is proposed to harvest the high-capacity and high-stability P'2-Na0.67Ti0.1Fe0.05Mn0.85O2 cathode. Quenching enables the formation of P'2-structure with a high Nae/Naf ratio of 2.1 (compared to the typical ∼ 1.00), delivering a higher capacity of 190.3 mAh g-1 at 0.1 C between 2.0 and 4.0 V (the naturally cooled cathode only exhibits 130.2 mAh g-1 at 0.1 C); Furthermore, Ti4+ (3d0, unfilled) and Fe3+ (3d5, half-filled) are introduced into P'2-Na0.67MnO2 for suppressing Na+/vacancy ordering and stabilizing the structure, resulting in excellent cycle stability with 96.9% capacity retention after 350 cycles at 5 C. This strategy provides a pathway to improve the reversible capacity of Mn-based layered cathodes for sodium-ion batteries.

Sodium-ion batteries (SIBs) are attracting attention as cost-effective alternatives to lithium-ion batteries (LIBs) for large-scale energy storage. Among SIB cathodes, P2-Na0.67Ni0.33Mn0.67O2 delivers high capacity and rate capability but suffers from rapid capacity fading under high-voltage charging due to a detrimental P2-O2 phase transition and interfacial side reactions. Here, we demonstrate a dual-modification strategy combining Cu2+ doping and MgO surface coating to address these challenges. The dual-modified cathode (Na0.67Ni0.28Cu0.05Mn0.67O2@MgO) delivers markedly improved performance: a high-capacity retention of 90.88% after 200 cycles at 1 C and significantly enhanced rate capability (95.23 mAh g-1 at 10 C). Ex situ XRD analyses reveal that the P2-O2 phase transition is effectively suppressed, leading to minimal structural change during cycling. DFT calculations reveal that the Cu-MgO dual modification synergistically enhances the electronic conductivity of the electrode and suppresses transition-metal layer gliding. The results indicate that Cu2+ doping enhances structural stability by regulating Na+/vacancy ordering and suppressing the high-voltage phase transition, whereas the MgO coating alleviates electrolyte-induced surface degradation and enhances Na+ diffusion kinetics. This work offers a valuable reference for designing high-performance cathode materials in sodium-ion battery systems.

High-voltage (>4.3 V) P2-type Mn-based layered oxides have emerged as promising cathode materials for sodium-ion batteries (SIBs), yet its practical application is impeded by irreversible oxygen redox reaction (ORR), Jahn-Teller distortion, and microcrack formation. Herein, an innovative high configurational entropy engineered hollow microsphere of Na0.67Li0.18Co0.08Mn0.71Mg0.13Cu0.08O2 (HEHM-NMO) as cathode material is proposed to realize stress self-dissipation and sustainable cationic/anionic redox, thereby endowing wide-temperature (-10-60 °C) workability for SIBs. It is found that the high configurational entropy enhances the electronic structure disorder (ESD) for impeding undesired oxygen escape and also optimizes the orbital hybridization (O 2p-Mn 3d) to induce reversible ORR (O2-/O2n-). By coupling high configurational entropy with hollow microspheres, spontaneous stress dissipation in HEHM-NMO is achieved during the cycling process. As a result, the HEHM-NMO cathode can provide an ultrahigh initial charge capacity of 171.7 mA h g-1 with an initial Coulombic efficiency of 92.9% at 1.5-4.5 V and still enable a retention of 85.8% after 300 cycles at 2C. Notably, it also shows a wide-temperature (-10-60 °C) workability, delivering a capacity of 152.0 mA h g-1 at -10 °C and 192.7 mA h g-1 at 60 °C (average decay: 0.12% per cycle). This work provides atomic-level insights into entropy-dominant structural and electronic regulation for activating reversible oxygen redox.

Cobalt Dissolution from Metal Oxides and Battery Cathode Materials with Acetic Acid-Based Deep Eutectic Solvents

Spinel zinc-cobalt oxide porous nanorod combined with reduced graphene oxide as an efficient cathode material for lithium-sulfur batteries

Effect of anion-doping on Na+ diffusion kinetics of NASICON-type cathode materials for Na-ion batteries

MgNiP2O7 pyrophosphate as a promising cathode material for magnesium-ion batteries: A computational investigation

Review on single-crystalline oxide cathode materials for next-generation Na-ion batteries

Theoretical study on strain engineering improving anchoring and catalytic performance of H/T-phase VS2 monolayer as cathode material for lithium-sulfur batteries

Transforming industrial by-products into high-value materials is crucial for sustainable development. The high-value conversion of industrial sodium sulfate (Na2SO4) by-product into a high-performance Na2.56Fe1.72(SO4)3/carbon (NFSO/KB) composite cathode material for sodium-ion batteries (SIBs) is studied. The cathode with a robust skeleton composed of [Fe2O10] dimers and [SO4] tetrahedra ensures excellent structural stability, and the unique three-dimensional (3D) framework facilitates rapid Na+ diffusion. Theoretical and structural analyses reveal that NFSO/KB possesses an ultralow Na+ migration barrier and a highly reversible reaction mechanism with minimal volume change (1.21%) during cycling. As a result, the cathode delivers a reversible capacity of 84.26mAhg-1 at 10mAg-1, with a high operating voltage of 3.8V (vs. Na/Na+). Moreover, it demonstrates a remarkable rate capability of 55.77mAhg-1 at 1000mAg-1 and exceptionally long cycle life (89.13% capacity retention after 3000 cycles). This work establishes a new paradigm for industrial by-products upcycling and provides a promising design strategy for low-cost, high-rate, and long-lifespan cathodes for SIBs.

Ni-rich cathode materials suffer from structural instability when cycled to high cutoff voltages. A transformation from the layered crystal structure to other phases, such as rocksalt, deteriorates the particle surface at low states of lithiation. Inhomogeneous potential and concentration fields as they occur in electrodes can have a significant impact on the degradation. In this work, we demonstrate rocksalt growth on a realistic high-energy NMC811 electrode using 3D microstructure-resolved simulations. We unravel inhomogeneities through transport in the electrode with a stronger active material degradation near the separator. To study individual particles in the electrode, we apply a watershed algorithm to segment the structure into distinct particles. A high correlation between both particle size as well as particle position and rocksalt thickness is observed in our half-cell simulations. We further shed light on inhomogeneities that can arise on single-particle level due to inhomogeneous lithiation.

Amid the escalating global environmental and energy crises, sodium-ion batteries (SIBs) are emerging as a significant complement to lithium-ion batteries (LIBs), owing to their high voltage platform, excellent safety, wide temperature range, and low cost. The choice of cathode materials plays a crucial role in influencing the efficiency and effectiveness of SIBs. Although layered cathode materials have shown promising prospects in specific capacity, voltage range, and environmental friendliness, they still face significant challenges due to factors like poor stability in air, interface degradation, and irreversible structural changes. Despite the low immediate economic benefits, the recycling of used SIBs has not been sufficiently addressed. As the adoption of SIBs grows, their recycling will present significant environmental and resource challenges in the future. This review starts with the synthesis of layered cathodes in SIBs and examines the failure mechanisms and improvement strategies during manufacturing and cycling, extending to the recovery of spent batteries. Through a comprehensive analysis, we aim to provide theoretical support and technical guidance for constructing the full life cycle value chain of new energy. The analysis in this paper includes innovations in materials and recycling technologies, extending to considerations of societal, ethical, and environmental aspects, especially how to balance corporate profits and social responsibility, and how recycling technologies can maximize resource utilization and environmental protection. Additionally, this review proposes a complete closed-loop system from production to recycling, emphasizing the sustainability of SIBs technology throughout its entire life cycle, offering a systematic framework and development direction for the future application of SIBs.

Fe and Ti co-doped LiCoPO4 as High-voltage Cathode Materials for Lithium-ion Batteries.

Acid etching-assisted spray-drying approaches to construct uniform ZrO2 coating layers on LiNi0.8Co0.1Mn0.1O2 cathode materials for high-performance lithium-ion batteries

Entropy-stabilized engineering enables stable high-voltage phosphate cathode materials for sodium-ion batteries