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The pursuit of high energy densities propels the design of next‐generation nickel‐based layered oxide cathodes. The utilization of low‐cobalt, ultrahigh‐nickel layered oxide cathodes, and the extension of operating voltages promise enhanced energy density. However, stability and safety face challenges associated with nickel content, including structural degradation, lattice oxygen evolution, and thermal instability. In this study, a promising strategy of Al and Nb dual‐bulk‐doping is presented in high‐Ni cathode materials of LiNi0.96Co0.04O2 (NC) to stabilize the bulk structure, suppress oxygen release, and attain superior electrochemical performance at high voltages. The introduction of Al and Nb effectively raises the migration energy of Ni2+ into Li sites and stabilizes lattice oxygen through strengthened Al─O and Nb─O bonds. Furthermore, the substitution of high‐valence Nb ions reduces the charge depletion of lattice oxygen and induces an ordered microstructure. The Al and Nb dual‐bulk‐doping strategy mitigates strain and stress associated with the H2↔H3 phase transition, reducing the generation and propagation of microcracks. The resulting Li(Ni0.96Co0.04)0.985Al0.01Nb0.005O2 (NCAN) cathode exhibits superior cycling stability, with a capacity retention of 77.8% after 300 cycles, even when operating at a high‐voltage of 4.4 V, outperforming the NC (48.5%). This work provides a promising perspective for developing high‐voltage and high‐Ni cathode materials. [ABSTRACT FROM AUTHOR]

Cobalt‐free ultrahigh‐nickel layered oxide cathodes hold great promise for reducing the cost and enhancing the energy density of Li‐ion batteries. However, the increasing Ni content and the elimination of Co could cause severe interfacial and structural degradation, leading to poor electrochemical performance of ultrahigh‐nickel layered oxide cathodes. Here, a Co‐free oxide, LiNi0.96Al0.03Ca0.01O2 (NAC), where Ca acts as pillar ions at the surface and Al works as an oxygen stabilizer across the bulk, is presented. An epitaxial layer rich in segregated Ca can effectively inhibit adverse surface reconstruction at high states of charge, together with the oxygen stabilization of bulk phase by doping Al, significantly reinforcing the structural rigidity of the layered oxide during cycling. The fabricated NAC cathode material exhibits exceptional electrochemical performance in terms of high cycling stability with 93% capacity retention over 500 cycles and a material‐level energy density of ~800 Wh kg−1. This study provides an efficient and feasible strategy to design and stabilize ultrahigh‐nickel oxides for lithium‐ion batteries. [ABSTRACT FROM AUTHOR]

The Compliant Golden‐Hooped Rod is a magical staff wielded by the Monkey King, Sun Wukong. The magical heavy Iron Rod was originally left inside Dragon Palace by Yu the Great, after taming the flood. In article number 1803477 Xue‐Ping Gao and co‐workers report the design of NiCo2O4 nanofibers, just like The Compliant Golden‐Hooped Rod in Dragon Palace. Inside a Li–S battery, the electrolyte with yellow soluble polysulfides (the yellow fish) is like the flood. NiCo2O4 nanofibers allow 'magical' catalytic conversion of soluble intermediate polysulfides by strong chemical interactions. Heavy NiCo2O4 nanofibers enhance the volumetric capacity of sulfurbased composites, like the stabilizing Iron Rod in the Sea. [ABSTRACT FROM AUTHOR]

Abstract Ni-rich layered oxides are regarded as the promising candidate for high energy density lithium-ion batteries owing to the high specific capacity. However, Ni-rich layered oxides suffer a rapid capacity fade, which is related to the undesirable structure evolution during cycling. Herein, an in-situ surface modification strategy by using Al 2 O 3 nanofibers as electrolyte additive is adopted to enhance the crystallographic, morphological, component, and electrochemical stability of LiNi 0.88 Co 0.09 Al 0.03 O 2 during cycling at both the particle and electrode level. The coating layer can be in-situ formed on the cathode surface after injecting the functional electrolyte into the cell. The integrated spherical morphology of secondary particles on the modified cathode is maintained during cycling without harmful microcracks. In the meantime, the coating layer protects the cathode from HF corrosion during cycling, which can reduce the dissolution of transition-metal ions and insure relatively uniform spatial distribution of the constituents across the cathode as detected by laser-induced breakdown spectroscopy (LIBS). Consequently, the modified cathode shows the improved stability with the high initial capacity of 198.1 mAh g−1 and good capacity retention after 800 cycles at room temperature. Moreover, the modified cathode also exhibits promising performance at higher operating temperature (55 °C) or higher charge potential (4.6 V). Graphical abstract Image 1 Highlights • Al2O3 nanofibers are introduced as novel additive to fabricate the functional electrolyte. • Structural, and cyclic stability of the cathode is improved by the functional electrolyte. • This work provides new insight of effective in-situ surface modification for Ni-rich oxides. [ABSTRACT FROM AUTHOR]