To pursue a higher energy density (>300 Wh kg−1 at the cell level) and a lower cost (<$125 kWh−1 expected at 2022) of Li‐ion batteries for making electric vehicles (EVs) long range and cost‐competitive with internal combustion engine vehicles, developing Ni‐rich/Co‐poor layered cathode (LiNi1−x−yCoxMnyO2, x+y ≤  0.2) is currently one of the most promising strategies because high Ni content is beneficial to high capacity (>200 mAh g−1) while low Co content is favorable to minimize battery cost. Unfortunately, Ni‐rich cathodes suffer from limited structure stability and electrode/electrolyte interface stability in the charged state, leading to electrode degradation and poor cycling performance. To address these problems, various strategies have been employed such as doping, structural optimization design (e.g., core–shell structure, concentration‐gradient structure, etc.), and surface coating. In this review, five key aspects of Ni‐rich/Co‐poor layered cathode materials are explored: energy density, fast charge capability, service life including cycling life and calendar life, cost and element resources, and safety. This enables a comprehensive analysis of current research advances and challenges from the perspective of both academy and industry to help facilitate practical applications for EVs in the future.

Stringed “tube on cube” hybrid architecture is developed for high-energy-density lithium–sulfur batteries with high sulfur loading and lean electrolyte.

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The notorious shuttling behaviors and sluggish conversion kinetics of the intermediate lithium polysulfides (LPS) are hindering the practical application of lithium sulfur (Li−S) batteries. Herein, an ultrafine, amorphous, and oxygendeficient niobium pentoxide nanocluster embedded in microporous carbon nanospheres (A-Nb 2 O 5−x @MCS) was developed as a multifunctional sulfur immobilizer and promoter toward superior shuttle inhibition and conversion catalyzation of LPS. The A-Nb 2 O 5−x nanocluster implanted framework uniformizes sulfur distribution, exposes vast active interfaces, and offers a reduced ion/electron transportation pathway for expedited redox reaction. Moreover, the low crystallinity feature of A-Nb 2 O 5−x manipulates the LPS chemical affinity, while the defect chemistry enhances the intrinsic conductivity and catalytic activity for rapid electrochemical conversions. Attributed to these superiorities, A-Nb 2 O 5−x @MCS delivers good Li−S battery performances, that is, high areal capacity of 6.62 mAh cm −2 under high sulfur loading and low electrolyte/sulfur ratio, superb rate capability, and cyclability over 1200 cycles with an ultralow capacity fading rate of 0.024% per cycle. This work provides a synergistic regulation on crystallinity and oxygen deficiency toward rapid and durable sulfur electrochemistry, holding a great promise in developing practically viable Li−S batteries and enlightening material engineering in related energy storage and conversion areas.

Rational construction of atomic‐scale interfaces in multiphase nanocomposites is an intriguing and challenging approach to developing advanced catalysts for both oxygen reduction (ORR) and evolution reactions (OER). Herein, a hybrid of interpenetrating metallic Co and spinel Co3O4 “Janus” nanoparticles stitched in porous graphitized shells (Co/Co3O4@PGS) is synthesized via ionic exchange and redox between Co2+ and 2D metal–organic‐framework nanosheets. This strategy is proven to effectively establish highways for the transfer of electrons and reactants within the hybrid through interfacial engineering. Specifically, the phase interpenetration of mixed Co species and encapsulating porous graphitized shells provides an optimal charge/mass transport environment. Furthermore, the defect‐rich interfaces act as atomic‐traps to achieve exceptional adsorption capability for oxygen reactants. Finally, robust coupling between Co and N through intimate covalent bonds prohibits the detachment of nanoparticles. As a result, Co/Co3O4@PGS outperforms state‐of‐the‐art noble‐metal catalysts with a positive half‐wave potential of 0.89 V for ORR and a low potential of 1.58 V at 10 mA cm−2 for OER. In a practical demonstration, ultrastable cyclability with a record lifetime of over 800 h at 10 mA cm−2 is achieved by Zn–air batteries with Co/Co3O4@PGS within the rechargeable air electrode.

Recent fruitful studies on rechargeable zinc-air battery have led to emergence of various bifunctional oxygen electrocatalysts, especially metal-based materials. However, their electrocatalytic configuration and evolution pathway during battery operation are rarely spotlighted. Herein, to depict the underlying behaviors, a concept named dynamic electrocatalyst is proposed. By selecting a bimetal nitride as representation, a current-driven "shell-bulk" configuration is visualized via time-resolved X-ray and electron spectroscopy analyses. A dynamic picture sketching the generation and maturation of nanoscale oxyhydroxide shell is presented, and periodic valence swings of performance-dominant element are observed. Upon maturation, zinc-air battery experiences a near twofold enlargement in power density to 234 mW cm −2 , a gradual narrowing of voltage gap to 0.85 V at 30 mA cm −2 , followed by stable cycling for hundreds of hours. The revealed configuration can serve as the basis to construct future blueprints for metal-based electrocatalysts, and push zinc-air battery toward practical application.

Large-sized two-dimensional phosphorus-doped carbon nanosheets (2D-PPCN) with tunable porosity were synthesized via a multifunctional templating method. A single inexpensive solid precursor, phosphorus pentoxide, is combined with common saccharides in a stepwise multiple templating process for 2D construction, phosphorus doping, and regulated micro-/mesopore creation. This reliable 2D porous carbon production technique can potentially be utilized in a variety of energy storage and conversion fields. The effects of different porous structures on the electrocatalytic activity of 2D-PPCN based electrocatalysts are specifically investigated in this work. The interconnected open-pore system and high specific surface area result in a high catalytic efficiency for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). When integrated into an air-breathing cathode for rechargeable Zn-air batteries, the best-performing 2D-PPCN demonstrates better cell performance than a noble metal benchmark catalyst and a higher durability with over 1000 charge–discharge cycles.