This review compares the intercalation behaviors of alkali metal ions in graphite, offers insight for the host-guest interaction mechanisms, and expands the intercalation chemistry of pure ions to complex anions, ion-solvent, and multivalent ions.

Porous structure design is generally considered to be a reliable strategy to boost ion transport and provide active sites for disordered carbon anodes of Na‐ion batteries (NIBs). Herein, a type of waste cork‐derived hard carbon material (CC) is reported for efficient Na storage via tuning the pore species. Benefiting from the natural holey texture of this renewable precursor, CCs deliver a novel hierarchical porous structure. The effective skeletal density test combined with small angle X‐ray scattering analysis (SAXS) is used to obtain the closed pore information. Based on a detailed correlation analysis between pore information and the electrochemical performance of CCs, improving pyrolysis temperature to reduce open pores (related to initial capacity loss) and increase closed pores (related to plateau capacity) endows an optimal CC with a high specific capacity of ≈360 mAh g−1 in half‐cells and a high energy density of 230 Wh kg−1 in full‐cells with a capacity retention of 71% after 2000 cycles at 2C rate. The bioinspired high temperature pore‐closing strategy and the new insights about the pore structure–performance relationship provide a rational guide for designing porous carbon anode of NIBs with tailored pore species and high Na storage capacity.

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Owing to the smaller Stokes radius and desolvation energy of Na + compared to those of Li + , an unusual ultralow-concentration electrolyte is proposed for Na-ion batteries to further reduce the cost and expand the working temperature range, benefiting from the low viscosity of a dilute electrolyte and the formed organic-dominated solid electrolyte interphase. The novel dilute electrolyte chemistry provides new solutions for the operation of rechargeable batteries under extreme conditions, which can accelerate the exploitation of low-cost and durable energy storage systems.

Nanostructured Fe 2 O 3 -graphene composite was successfully fabricated through a facile solution-based route under mild hydrothermal conditions. Well-crystalline Fe 2 O 3 nanoparticles with 30-60 nm in size are highly encapsulated in graphene nanosheet matrix, as demonstrated by various characterization techniques. As electrode materials for supercapacitors, the as-obtained Fe 2 O 3 -graphene nanocomposite exhibits large specific capacitance (151.8 F g −1 at 1 A g −1 ), good rate capability (120 F g −1 at 6 A g −1 ), and excellent cyclability. The significantly enhanced electrochemical performance compared with pure graphene and Fe 2 O 3 nanoparticles may be attributed to the positive synergetic effect between Fe 2 O 3 and graphene. In virtue of their superior electrochemical performance, they will be promising electrode materials for high-performance supercapacitors applications.

In this paper, we construct a generalized Darboux transformation to the coupled Hirota equations with high-order nonlinear effects like the third dispersion, self-steepening and inelastic Raman scattering terms. As application, an Nth-order localized wave solution on the plane backgrounds with the same spectral parameter is derived through the direct iterative rule. In particular, some semi-rational, multi-parametric localized wave solutions are obtained:(1) Vector generalization of the first-and the second-order rogue wave solution; (2) Interactional solutions between a dark-bright soliton and a rogue wave, two dark-bright solitons and a second-order rogue wave; (3) Interactional solutions between a breather and a rogue wave, two breathers and a second-order rogue wave. The results further reveal the striking dynamic structures of localized waves in complex coupled systems.

In this work, we describe our efforts to produce Mn3O4–graphene nanocomposites based on a convenient andfeasible solution based synthetic route under mild conditions. According to transmission electron microscopy (TEM) and high angle annular dark field scanning transmission electron microscopy (HAADF‐STEM) results porous Mn3O4 nanocrystals (NCs), 20–40 nm in size, are uniformly deposited on both sides of the graphene nanosheet (GNS) matrix. Significantly, the as‐prepared Mn3O4–graphene nanocomposites exhibit remarkable pseudocapacitive activity including high specific capacitance (236.7 F g–1 at 1 A g–1), good rate capability (133 F g–1 at 8 A g–1), and excellent cyclability (the specific capacitance only decreases by 6.32 % of the initial capacitance after 1000 cycles). The excellent pseudocapacitive performance of the Mn3O4–graphene nanocomposites electrode is probably due to the positive synergistic effects between the Mn3O4 and GNS. Namely, the intimate combination of the conductive graphene network with uniformly dispersed porous Mn3O4 NCs not only greatly improves the electrochemical utilization of Mn3O4, but also increases the double‐layer capacitance of the graphene sheets. These characteristics make this nanocomposite a very promising electrode material for high performance supercapacitors.

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