Search

Zn‐I2 batteries have attracted attention due to their low cost, safety, and environmental friendliness. However, their performance is still limited by the irreversible growth of Zn dendrites, hydrogen evolution reactions, corrosion, and shuttle effect of polyiodide. In this work, we have prepared a new porous polymer (CD‐Si) by nucleophilic reaction of β‐cyclodextrin with SiCl4, and CD‐Si is applied to the solid polymer electrolyte (denoted PEO/PVDF/CD‐Si) to solve above‐mentioned problems. Through the anchoring of the CD‐Si, a conductive network with dual transmission channels was successfully constructed. Due to the non‐covalent anchoring effect, the ionic conductivity of the solid polymer electrolytes (SPE) can reach 1.64×10−3 S cm−1 at 25 °C. The assembled symmetrical batteries can achieve highly reversible dendrite‐free galvanizing/stripping (stable cycling for 7500 h at 5 mA cm−2 and 1200 h at 20 mA cm−2). The solid‐state Zn‐I2 battery shows an ultra‐long life of over 35,000 cycles at 2 A g−1. Molecular dynamics simulations are performed to elucidate the working mechanism of CD‐Si in the polymer matrix. This work provides a novel strategy towards solid electrolytes for Zn‐I2 batteries. [ABSTRACT FROM AUTHOR]

Self‐standing carbon‐based substrates with satisfied structural stability and property adjustability have promising applications in flexible lithium (Li) metal batteries (FLMBs). Current strategies for modifying carbon materials are normally carried out on powder carbon, and very few of them are suitable for self‐standing carbon substrates. Herein, a pore‐forming strategy based on the redox chemistry of metallic oxide nanodots is developed to prepare two porous carbon substrates for anode and cathode. Starting with cotton cloth, the resulting hollow carbon fibers substrate with nanopores effectively prevents from Li dendrites formation and large volume change in lithium metal anode (LMA). Simulations indicate that the porous structure leads to homogeneous ion flux, Li‐ion concentration, and electric field during Li deposition. Li symmetrical cell based on this substrate remains stable for 8300 h with an ultralow voltage hysteresis of 9 mV. Via a similar route, porous carbon cloth substrate is obtained for subsequently seeding V2O5 nanowires to prepare the cathode. The assembled FLMBs pouch cell delivers a capacity of 8.2 mAh with a high capacity retention of ~100% even under dramatic deformation. The demonstrated strategy has far‐reaching potential in preparing free‐standing porous carbon‐based materials for flexible energy storage devices. [ABSTRACT FROM AUTHOR]

Theoretical study of the stereo-dynamics of the reaction, H + [HeH.sup.+] (v = 0, j = 0) → [H.sup.+.sub.2] + He, have been performed with quasi-classical trajectory (QCT) method at different collision energies on a new ab initio potential energy surface. The distributions of P([θ.sub.r]), P([θ.sub.r]) and four generalized polarization-dependent differential cross-sections have been calculated. The results indicate that both the orientation and alignment of the rotational angular momentum are impacted by collision energies. With the collision energy increases, the rotation of the product molecule has a preference of changing from the 'in-plane' reaction mechanism to the 'out-of-plane' mechanism. Although the reaction is mainly dominated by the direct reaction mechanism, the indirect mechanism plays a role while the collision energy is very low. PACS No: 34.10.+X Nous avons fait une etude de la dynamique tridimensionnelle de la reaction H + [HeH.sup.+] (v = 0, j = 0) → [H.sup.+.sub.2] + He, a l'aide de la meethode des quasi-trajectoires (QCT) a diffeerentes energies de collision sur une nouvelle surface d'energie obtenue ab initio. Nous avons calcule; les distributions P([θ.sub.r]), P([φ.sub.r]) et quatre sections efficaces diffeerentielles geeneralisees dependant de la polarisation. Les resultats indiquent que les deux orientations et l'alignement du moment angulaire de rotation sont affectes par l'energie des collisions. Lorsque l'energie de la collision augmente, la rotation de la molecule produite a le choix de passer du mecanisme dans le plan au mecanisme hors plan. Meme si la reaction est majoritairement dominee par le mecanisme de reaction directe, le mecanisme indirect joue un role lorsque l'energie est tres basse. [Traduit par la Redaction], 1. Introduction In recent decades, the reaction of He + [H.sup.+.sub.2] has received considerable attention for its importance in the studies of ion-molecule reaction dynamics [1-11]. In 2000, Aquilanti et [...]

Preparation of a material with excellent rate performance and high capacity contribution is significant for sodium-ion hybrid capacitors (SIHCs). TiO2 has been extensively studied due to its outstanding chemical stability, but the low specific capacity greatly hinders its practical application. Herein, TiO2 with a foveolate-shape is prepared via a precisely controlled Ostwald maturation procedure. Benefiting from the unique structure, foveolate TiO2 possesses satisfactory electrochemical performance. When used as the anode for SIHCs, a high reversible specific capacity of 290 mA h g−1 is obtained with an ultrahigh initial coulombic efficiency of 96% at 100 mA g−1. Even if the current density increases to 1000 mA g−1, the specific discharge capacity can still be maintained at 158 mA h g−1 after 1500 cycles. To further improve its capacity, the TiO2@MoSe2 composite electrode is synthesized by using foveolate TiO2 as the skeleton for the successful growth of MoSe2 nanosheets. A higher reversible specific capacity of 551 mA h g−1 is achieved at 100 mA g−1. Moreover, a reversible specific capacity of 164 mA h g−1 is maintained after 500 cycles at 5000 mA g−1. The foveolate TiO2 preparation method developed in this work provides new ideas for the development of both substrate materials and active materials in the field of energy storage. [ABSTRACT FROM AUTHOR]