High-entropy doping promising ultrahigh-Ni Co-free single-crystalline cathode toward commercializable high-energy lithium-ion batteries.

The development of advanced layered Ni-rich cathodes is essential for high-energy lithium-ion batteries (LIBs). However, the prevalent Ni-rich cathodes are still plagued by inherent issues of chemomechanical and thermal instabilities and limited cycle life. For this, here, we introduce an efficient approach combining single-crystalline (SC) design with in situ high-entropy (HE) doping to engineer an ultrahigh-Ni cobalt-free layered cathode of LiNi0.88Mn0.03Mg0.02Fe0.02Ti0.02Mo0.02Nb0.01O2 (denoted as HE-SC-N88). Thanks to the SC- and HE-doping merits, HE-SC-N88 is featured with a grain-boundary-free and stabilized structure with minimal lattice strain, preventing mechanical degradation, reducing surface parasitic reactions, and mitigating oxygen loss. Accordingly, our HE-SC-N88 cathode demonstrates exceptional electrochemical properties particularly with prolonged cycling stability under strenuous conditions in both half and full cells, and the delayed O loss-induced phase transitions upon heating. More meaningfully, our design of HE doping in redefining the ultrahigh-Ni Co-free SC cathodes will make a tremendous progress toward industrial application of next-generation LIBs.

Chemomechanically Stable Small Single-crystal Mo-doped LiNi0.6 Co0.2 Mn0.2 O2 Cathodes for Practical 4.5†V-class Pouch-type Li-ion Batteries.

High voltage can cost-effectively boost energy density of Ni-rich cathodes based Li-ion batteries (LIBs), but compromises their mechanical, electrochemical and thermal-driven stability. Herein, a collaborative strategy (i.e., small single-crystal design and hetero-atom doping) is devised to construct a chemomechanically reliable small single-crystal Mo-doped LiNi0.6 Co0.2 Mn0.2 O2 (SS-MN6) operating stably under high voltage (≥4.5 V vs. Li/Li+ ). The substantially reduced particle size combined with Mo6+ doping absorbs accumulated localized stress to eradicate cracks formation, subdues the surface side reactions and lattice oxygen missing meanwhile, and improves thermal tolerance at highly delithiated state. Consequently, the SS-MN6 based pouch cells are endowed with striking deep cycling stability and wide-temperature-tolerance capability. The contribution here provides a promising way to construct advanced cathodes with superb chemomechanical stability for next-generation LIBs.

Construction of Hierarchical Nanotubes Assembled from Ultrathin V3 S4 @C Nanosheets towards Alkali-Ion Batteries with Ion-Dependent Electrochemical Mechanisms.

Ultrathin core-shell V3 S4 @C nanosheets assembled into hierarchical nanotubes (V3 S4 @C NS-HNTs) are synthesized by a self-template strategy and evaluated as general anodes for alkali-ion batteries. Structural/physicochemical characterizations and DFT calculations bring insights into the intrinsic relationship between crystal structures and electrochemical mechanisms of the V3 S4 @C NS-HNTs electrode. The V3 S4 @C NS-HNTs are endowed with strong structural rigidness owing to the layered VS2 subunits and interlayer occupied V atoms, and efficient alkali-ion adsorption/diffusion thanks to the electroactive V3 S4 -C interfaces. The resulting V3 S4 @C NS-HNTs anode exhibit distinct alkali-ion-dependent charge storage mechanisms and exceptional long-durability cyclic performance in storage of K+ , benefiting from synergistic contributions of pseudocapacitive and reversible intercalation/de-intercalation behaviors superior to those of the conversion-reaction-based Li+ -/Na+ -storage counterparts.

Bottom-Up Fabrication of 1D Cu-based Conductive Metal-Organic Framework Nanowires as a High-Rate Anode towards Efficient Lithium Storage.

Conductive metal-organic frameworks (MOFs), as a newly emerging multifunctional material, hold enormous promise in electrochemical energy-storage systems owing to their merits including good electronic conductivity, large surface area, appropriate pore structure, and environmental friendliness. In this contribution, a scalable solvothermal strategy was devised for the bottom-up fabrication of 1D Cu-based conductive MOF, that is, Cu3 (2,3,6,7,10,11-hexahydroxytriphenylene)2 (Cu-CAT) nanowires (NWs), which were further utilized as a competitive anode for lithium-ion batteries (LIBs). The intrinsic Li storage mechanism of the Cu-CAT electrode was also explored. Benefiting from its structural virtues, the resultant 1D Cu-CAT NWs were endowed with superb Li+ diffusion coefficients and electrochemical conductivities and exhibited remarkably high-rate reversible capacities of approximately 631 mAh g-1 at 0.2 A g-1 and even approximately 381 mAh g-1 at 2 A g-1 , along with striking capacity retention of 81 % after 500 cycles at 0.5 A g-1 . In addition, a Cu-CAT NWs-based full cell assembled with LiNi0.8 Co0.1 Mn0.1 O2 as the cathode displayed a large energy density of approximately 275 Wh kg-1 as well as excellent cycling behavior. These results manifest the promising application of 1D conductive Cu-CAT NWs in advanced LIBs and even other potential versatile energy-related fields.

General and Scalable Fabrication of Core-Shell Metal Sulfides@C Anchored on 3D N-Doped Foam toward Flexible Sodium Ion Batteries.

Flexible self-standing transitional metal sulfides (TMSs)/carbon nanoarchitectures have attracted widespread research interests for sodium ion batteries (SIBs), thanks to their enormous capability to address intrinsic issues of TMSs for SIBs applications. However, controllable synthesis of hierarchical hybrid structures is always laborious and involves complicated procedures. Herein, a simple yet general and scalable adsorption-annealing strategy is first devised to finely construct core-shell carbon-coated TMSs (TMSs@C, including Co9 S8 @C, FeS@C, Ni3 S2 @C, MnS@C, and ZnS@C) nanoparticles anchored on 3D N-doped carbon foam (3DNCF) via the coordination and hydrogen-bond adsorption. Benefiting from synergistic contributions from strong chemical affinity between nanodimensional TMSs and 3DNCF, efficient electronic/ionic transport channels, as well as a uniform carbon accommodating layer, the resulted self-standing TMSs@C/3DNCF electrodes exhibit distinguished sodium storage performances, including large reversible capacities, high rate behaviors, and exceptional long-span cycle stability in both half cells and flexible full devices. More significantly, the smart methodology developed holds huge promise for commercialization of binder-free TMSs@C/3DNCF anodes toward advanced flexible SIBs.

Ultralong Layered NaCrO2 Nanowires: A Competitive Wide-Temperature-Operating Cathode for Extraordinary High-Rate Sodium-Ion Batteries.

The development of high-rate cathodes particularly with remarkable wide-temperature-tolerance sodium-storage capability plays a significant role in commercial applications of sodium-ion batteries (SIBs). Herein, we devise a scaled-up electrospinning avenue to fabricate nanocrystal-constructed ultralong layered NaCrO2 nanowires (NWs) toward SIBs as a wide-temperature-operating cathode. The resultant one-dimensional (1D) NaCrO2 nanoarchitecture is endowed with orientated and shortened electronic/ionic transport and remarkable structural tolerance to stress change over sodiation-desodiation processes. Benefiting from these structural superiorities, the NaCrO2 NWs are featured with prominent Na+-storage behaviors in the wide-operating-temperature range from -15 to 55 °C. Promisingly, the NaCrO2 NWs exhibit extraordinary high-rate capacities of ∼108.8 and ∼87.2 mAh g-1 at 10 and 50 C rates at 25 °C, and even 94.6 (55 °C) and ∼60.1 (-15 °C) mAh g-1 at 10 C, along with outstanding cyclic stabilities with capacity retentions of ∼80.6% (-15 °C), 88.4% (25 °C), and ∼86.9% (55 °C). The overall performance of our NaCrO2 is superior to other reported NaCrO2-based cathodes, even with conductive nanocarbon coating. Encouragingly, a competitive energy density of ∼161 Wh kg-1 can be obtained by the NaCrO2 NWs-based full cell. Therefore, our NaCrO2 NWs can be highly anticipated as advanced cathode for commercial wide-temperature-tolerance SIBs.

Nasicon-Type Surface Functional Modification in Core-Shell LiNi0.5Mn0.3Co0.2O2@NaTi2(PO4)3 Cathode Enhances Its High-Voltage Cycling Stability and Rate Capacity toward Li-Ion Batteries.

Surface modifications are established well as efficient methodologies to enhance comprehensive Li-storage behaviors of the cathodes and play a significant role in cutting edge innovations toward lithium-ion batteries (LIBs). Herein, we first logically devised a pilot-scale coating strategy to integrate solid-state electrolyte NaTi2(PO4)3 (NTP) and layered LiNi0.5Mn0.3Co0.2O2 (NMC) for smart construction of core-shell NMC@NTP cathodes. The Nasicon-type NTP nanoshell with exceptional ion conductivity effectively suppressed gradual encroachment and/or loss of electroactive NMC, guaranteed stable phase interfaces, and meanwhile rendered small sur-/interfacial electron/ion-diffusion resistance. By benefiting from immanently promoting contributions of the nano-NTP coating, the as-fabricated core-shell NMC@NTP architectures were competitively endowed with superior high-voltage cyclic stabilities and rate capacities within larger electrochemical window from 3.0 to 4.6 V when utilized as advanced cathodes for advanced LIBs. More meaningfully, the appealing electrode design concept proposed here will exert significant impact upon further constructing other high-voltage Ni-based cathodes for high-energy/power LIBs.

Recent Progresses and Development of Advanced Atomic Layer Deposition towards High-Performance Li-Ion Batteries.

Electrode materials and electrolytes play a vital role in device-level performance of rechargeable Li-ion batteries (LIBs). However, electrode structure/component degeneration and electrode-electrolyte sur-/interface evolution are identified as the most crucial obstacles in practical applications. Thanks to its congenital advantages, atomic layer deposition (ALD) methodology has attracted enormous attention in advanced LIBs. This review mainly focuses upon the up-to-date progress and development of the ALD in high-performance LIBs. The significant roles of the ALD in rational design and fabrication of multi-dimensional nanostructured electrode materials, and finely tailoring electrode-electrolyte sur-/interfaces are comprehensively highlighted. Furthermore, we clearly envision that this contribution will motivate more extensive and insightful studies in the ALD to considerably improve Li-storage behaviors. Future trends and prospects to further develop advanced ALD nanotechnology in next-generation LIBs were also presented.