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Lithium/sodium–selenium (Li/Na–Se) batteries with high volumetric specific capacity are considered promising as next‐generation battery technologies. However, their practical application is hindered by challenges such as low Se loading in cathodes and the polyselenides shuttle effect. To address these challenges, a new Se host is introduced in the form of a free‐standing N, O co‐doped vertically aligned porous carbon framework decorated with a carbon nanotube forest (VCF‐CNTs), allowing for high mass loading of up to 16 mg cm−2. The low‐tortuosity Se@VCF‐CNTs architecture facilitates rapid lithiation/sodiation kinetics, while the CNT forests in vertical microchannels enhance efficient Se loading and serve as a multi‐layer fence to prevent undesired polyselenide shuttling. Consequently, the Se@VCF‐CNTs cathode displays a significant areal capacity of 10.3 mAh cm−2 at 0.1 C with a Se loading of 16 mg cm−2 for Li–Se batteries, exceeding that of commercial lithium ion batteries (4.0 mAh cm−2). In Na–Se batteries, the Se@VCF‐CNTs electrode with a Se loading of 5 mg cm−2 exhibits a discharge capacity of 436 mAh g−1 after 200 cycles, proving its consistent cycling performance. This study enriches the field of knowledge concerning high‐loading Se‐based battery systems, offering a promising avenue for enhancing energy density in the field. [ABSTRACT FROM AUTHOR]

Dual‐ion batteries, as one of the most promising alternatives to Li‐ion batteries, face severe challenges in terms of side reactions, particularly at the anode. These side reactions result in the consumption of limited cations and the deactivation of anions in graphite during cycling. To date, most reports are focused on reducing these side reactions. Here, a new way is proposed to achieve the stable cycling of dual‐ion batteries using Mg as an example. Mg can be oxidized to Mg2+ during the discharge process, thereby replenishing the cation loss due to the side reactions. Meanwhile, anions are released from graphite to maintain the charge balance in the electrolyte. Another advantage is that the formation of Li3Mg7 during cycles facilitates Li plating/stripping. Therefore, Mg||Graphite exhibits a high Coulombic efficiency (≈96.5%) and a stable cycling performance (≈94.6% after 1700 cycles at 2 C) even without prelithiation, much better than Cu||Graphite and Graphite||Graphite. The mechanism also works for other active metals, such as K, Ca, and Na. The results demonstrate the promising potential of this strategy. [ABSTRACT FROM AUTHOR]

TiO2‐based materials are considered to be the promising anodes of sodium‐ion batteries (NIBs) because of their high safety and good stability. However, their low specific capacity and high safety operating voltage plateau impose a severe challenge for high energy density batteries. Herein, interconnected micro‐sheets consisting of carbon nanotubes and sulfur doped TiO2 (CNT/S‐TiO2) are synthesized via an ultrasonic process and subsequent calcination, enabling the fabrication of high‐performance material. The utilization of SWCNT overcomes the structure instabilities during electrode preparation of thick electrodes. The incorporation of SWCNT and sulfur dopants in the CNT/S‐TiO2 composite not only enhances conductivity but also improves ion transport dynamics, resulting in rapid charge delivery and high specific capacity at the thick electrode level. Consequently, CNT/S‐TiO2 demonstrates excellent rate performance (from 0.3 to 15 C, with 72.4% capacity retention) and long cycling stability (10000 cycles at a load of 1.96 mg cm−2). More importantly, the high S‐TiO2 content (90%) in the thick electrode (21.2 mg cm−2) achieves a high areal capacity retention of 3.4 mA h cm−2 after 100 cycles, which surpasses the actual application requirements. [ABSTRACT FROM AUTHOR]

Shuttle effect and sluggish redox kinetics of sulfur species still hinder the practical application of lithium‐sulfur batteries (LSBs). Herein, a strategy of integrating sub‐nano catalysts into metal‐organic framework (MOF) is proposed for developing efficient sulfur host to tackle these issues. The designed MOF host (MOF‐TOC) endowed with sub‐nano TiO clusters (TOCs) in the mesopores of MOF can act as an efficient reaction chamber in LSBs. Systematic electrochemical measurements and calculations demonstrate that MOF‐TOC can trap and confine lithium polysulfides (LiPSs) via strong chemical interaction. Moreover, the highly active TOCs isolated in different nanopores can accelerate the bidirectional redox reaction of sulfur species through the d‐p orbital hybridization with sulfur species. Benefiting from these merits, MOF‐TOC delivers LSBs with remarkably improved areal capacity and cycling stability at high sulfur loadings and lean electrolytes. This work gives insight into the rational design of catalyst‐containing MOF hosts and will shed light on the development of advanced catalytic hosts for high‐performance LSBs. [ABSTRACT FROM AUTHOR]

Graphite‐derived carbon materials have been widely used in metal‐ion batteries due to their good mechanical and electrical properties, cost effectiveness, light weight, and environmental friendliness. Though natural graphite has been commercially used in lithium‐ion batteries, the small interlayer spacing hinders its application in other metal‐ion batteries. As such, numerous works have been done to enhance the metal‐ion storage capability of graphite and its derivatives. In this review, structural engineering on graphite including expanded graphite, graphite intercalation compounds and porous graphite, and the corresponding electrolyte engineering for lithium‐ion batteries, sodium ion batteries, potassium ion batteries, and dual ion batteries are summarized, aiming to make a comparison between various strategies and give a suggestion on future work in this area. [ABSTRACT FROM AUTHOR]