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O3-type NaNi1/3Fe1/3Mn1/3O2 (NFM) is one of the most representative cathode materials with low cost and high capacity advantages. However, the sluggish diffusion kinetics and severe cathode–electrolyte interfacial reaction are serious roadblocks to commercialization. Hereby, a novel method of in situ V-modification is well-designed to play dual roles in reconstructing the crystal lattice and interface structure. Notably, the broadened layer spacing of O–Na–O and shortened TM–O bond are attributed to successful doping of V5+ into the bulk, accelerating the transmission of sodium ions and improving the structure stability. Concomitantly, the construction of a thin surface coating layer is beneficial for mitigating volume expansion and inhibiting structural degradation, which is validated by in situ X-ray diffraction coupled with the synchrotron X-ray absorption spectroscopy. Consequently, the rationally designed V-modified NFM cathode exhibits excellent cycling performances, exhibiting great capacity retention of 75.8% after 500 cycles at 2C in a half cell, and 85.6% capacity retention is observed after 150 cycles at 1C in the full cell. This work provides new insights into the development of O3-type layered oxide cathodes toward long-cycle life applications for large-scale energy storage systems. [ABSTRACT FROM AUTHOR]

The structural failure of Na2Mn[Fe(CN)6] could not be alleviated with traditional modification strategies through the adjustable composition property of Prussian blue analogues (PBAs), considering that the accumulation and release of stress derived from the MnN6 octahedrons are unilaterally restrained. Herein, a novel application of adjustable composition property, through constructing a coordination competition relationship between chelators and [Fe(CN)6]4− to directionally tune the enrichment of elements, is proposed to restrain structural degradation and induce unconventional energy coupling phenomenon. The non‐uniform distribution of elements at the M1 site of PBAs (NFM‐PB) is manipulated by the sequentially precipitated Ni, Fe, and Mn according to the Irving‐William order. Electrochemically active Fe is operated to accompany Mn, and zero‐strain Ni is modulated to enrich at the surface, synergistically mitigating with the enrichment and release of stress and then significantly improving the structural stability. Furthermore, unconventional energy coupling effect, a fusion of the electrochemical behavior between FeLS and MnHS, is triggered by the confined element distribution, leading to the enhanced electrochemical stability and anti‐polarization ability. Consequently, the NFM‐PB demonstrates superior rate performance and cycling stability. These findings further exploit potentialities of the adjustable composition property and provide new insights into the component design engineering for advanced PBAs. [ABSTRACT FROM AUTHOR]

Na4Mn1.5Fe1.5(PO4)2P2O7 (NMFPP), with its low cost and high energy density, is essential for accelerating the commercialization of sodium‐ion batteries. However, its practical application is limited by serious voltage hysteresis and detrimental Jahn‐Teller distortions. Herein, a high operating voltage and superior stable Nb‐doped NMFPP with fewer intrinsic anti‐site defects are elaborately designed by the reconstruction of the crystal lattice and electronic distribution. By introducing higher charge density Nb─O bonds, the lengths of Mn‐O bonds are shortened, enhancing lattice stability. As a result, the lattice volume contracted during Na+ extraction/insertion is decreased with niobium‐modified Na4(Mn0.5Fe0.5)2.94Nb0.06(PO4)2P2O7, mitigating lattice distortion from the Jahn‐Teller effect and increasing the capacity retention after 1000 cycles from 57.5% to 82.3%. More importantly, the delayed effect of Mn2+ involvement in redox reactions is significantly reduced, raising the average operating voltage from 3.32 to 3.64 V and increasing the overall energy density by 13%. This study opens new avenues to develop advanced sodium‐ion battery cathode materials with high energy density and long calendar life for energy storage. [ABSTRACT FROM AUTHOR]

Recycling spent lithium-ion batteries (LIBs) in a green and economical way is vital for maintaining the sustainability of the LIB industry. However, given the low content of high-value components in olivine-type lithium iron phosphate (LFP), traditional metallurgical processes are economically unfeasible for recycling due to high chemical/energy consumption and labor-intensive procedures. This study proposes a facile electrochemistry strategy to directly regenerate the spent LFP material by an electrically driven lithiation process as a spent LFP slurry (200 g/L) rather than as electrodes. Minimal energy and chemical consumption are achieved by enabling the healing of spent LFP without destroying the original olivine-type crystal structure. The proposed method utilizes mild healing conditions (25 °C for 2 h) and LiCl solution as the only reagent in the regeneration process, significantly lowering the expenses associated with producing cathode electrodes. The electrochemical performance of the regenerated LFP have been dramatically recovered after regeneration, exhibiting a capacity of 151.5 mA h g -1 at 0.1 C and 96.6% capacity retention over 400 cycles at 1 C. This approach demonstrates a high processing capability and offers considerable economic and environmental benefits, making it an eco-friendly option and supporting the sustainable development of the LFP industry.

Transition metal selenides (TMSs) are receiving considerable interest as improved anode materials for sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs) due to their considerable theoretical capacity and excellent redox reversibility. Herein, ZIF-12 (zeolitic imidazolate framework) structure is used for the synthesis of Cu 2 Se/Co 3 Se 4 @NPC anode material by pyrolysis of ZIF-12/Se mixture. When Cu 2 Se/Co 3 Se 4 @NPC composite is utilized as an anode electrode material in LIB and SIB half cells, the material demonstrates excellent electrochemical performance and remarkable cycle stability with retaining high capacities. In LIB and SIB half cells, the Cu 2 Se/Co 3 Se 4 @NPC anode material shows the ultralong lifespan at 2000 mAg -1 , retaining a capacity of 543 mAhg -1 after 750 cycles, and retaining a capacity of 251 mAhg -1 after 200 cycles at 100 mAg -1 , respectively. The porous structure of the Cu 2 Se/Co 3 Se 4 @NPC anode material can not only effectively tolerate the volume expansion of the electrode during discharging and charging, but also facilitate the penetration of electrolyte and efficiently prevents the clustering of active particles. In situ X-ray difraction (XRD) analysis results reveal the high potential of Cu 2 Se/Co 3 Se 4 @NPC composite in building efficient LIBs and SIBs due to reversible conversion reactions of Cu 2 Se/Co 3 Se 4 @NPC for lithium-ion and sodium-ion storage., (© 2024 Wiley‐VCH GmbH.)

Ni/Mn-based oxide cathode materials have drawn great attention due to their high discharge voltage and large capacity, but structural instability at high potential causes rapid capacity decay. How to moderate the capacity loss while maintaining the advantages of high discharge voltage remains challenging. Herein, the replacement of Mn ions by Ga ions is proposed in the P2-Na 2/3 Ni 0.2 Mn 0.8 O 2 cathode for improving their cycling performances without sacrificing the high discharge voltage. With the introduction of Ga ions, the relative movement between the transition metal ions is restricted and more Na ions are retained in the lattice at high voltage, leading to an enhanced redox activity of Ni ions, validated by ex situ synchrotron X-ray absorption spectrum and X-ray photoelectron spectroscopy. Additionally, the P2-O2 phase transition is replaced by a P2-OP4 phase transition with a smaller volume change, reducing the lattice strain in the c-axis direction, as detected by operando/ex situ X-ray diffraction. Consequently, the Na 2/3 Ni 0.21 Mn 0.74 Ga 0.05 O 2 electrode exhibits a high discharge voltage close to that of the undoped materials, while increasing voltage retention from 79% to 93% after 50 cycles. This work offers a new avenue for designing high-energy density Ni/Mn-based oxide cathodes for sodium-ion batteries., (© 2023 Wiley‐VCH GmbH.)