Single-atom catalysts have been paid more attention to improving sluggish reaction kinetics and anchoring polysulfide for lithium−sulfur (Li−S) batteries. It has been demonstrated that d-block single-atom elements in the fourth period can chemically interact with the local environment, leading to effective adsorption and catalytic activity toward lithium polysulfides. Enlightened by theoretical screening, for the first time, we design novel single-atom Nb catalysts toward improved sulfur immobilization and catalyzation. Calculations reveal that Nb−N 4 active moiety possesses abundant unfilled antibonding orbitals, which promotes d-p hybridization and enhances anchoring capability toward lithium polysulfides via a "trapping−coupling−conversion" mechanism. The Nb−SAs@NC cell exhibits a high capacity retention of over 85% after 1000 cycles, a superior rate performance of 740 mA h g −1 at 7 C, and a competitive areal capacity of 5.2 mAh cm −2 (5.6 mg cm −2 ). Our work provides a new perspective to extend cathodes enabling high-energy-density Li−S batteries.

Developing "ideal" binders to achieve ultrahigh area-capacity stable silicon (Si) anodes remains a significant challenge. Herein, a self-healing binder with a multilevel buffered structure is designed to alleviate the structural damage and performance degradation caused by extreme volume deformation of Si. In this multilevel configuration, employing the coexistence strategy of dynamic supramolecular interactions and rigid covalent bonds, the dopamine-grafted poly(acrylic acid) (PAA-DA) possesses abundant hydrogen bonds and strong viscoelasticity, which facilitates the dynamic reconstruction of the entire network. Moreover, the hydroxyl groups on the polyethylene glycol (PVA) form a strong covalent bond network with the carboxyl groups in PAA-DA under thermal polymerization conditions to ensure the integrity of the electrode structure. At 4 A g −1 , the resulting Si electrode retains 1974.1 mAh g −1 after 500 cycles. This binder design strategy with dynamic repair and stable network structure gives specific inspiration for developing high-energy-density batteries.

No abstract

No abstract

With the development of flexible devices, it is necessary to design high-performance power supplies with superior flexibility, durability, safety, etc., to ensure that they can be deformed with the device while retaining their electrochemical functions. Herein, we have designed a flexible lithium-ion battery inspired by the DNA helix structure. The battery structure is mainly composed of multiple thick energy stacks for energy storage and some grooves for stress buffers, which realized the spiral deformation of batteries. According to the results, the batteries exhibit less than 3% capacity degradation even after more than 31000 times of in situ dynamic mechanical loadings. Moreover, the mechanism of the battery with spiral deformability is further revealed. It is anticipated that this bioinspired design strategy could create unique opportunities for the commercialization of flexible batteries and fill the current gap in realizing battery-specific deformations to meet various requirements for future complex device designs.