Nickel phosphides as anode materials for lithium-ion batteries (LIBs) have attracted much attention due to their large theoretical capacities and great phase diversity. However, the obstacles of large volume expansions, sluggish Li diffusion kinetics, and poor reversibility hinder their practical applications. Herein, we introduce Ge into the Ni–P system using a mechanical alloying method to synthesize Ni–Ge–P composites as novel anodes for LIBs. The results show that the Ge-substituted Ni₂Ge_0.5P_0.5, NiGe_0.5P_0.5, and NiGeP₂ compounds of the Ni–Ge–P composites possess higher crystal symmetry and larger cell volumes than the structurally similar Ni₂P, NiP, and NiP₃, respectively. When used as anodes, the Ni–Ge–P anodes exhibit enhanced electrochemical reversibility and reduced redox potential compared to the Ni–P anodes. Furthermore, the Li-storage mechanism of a selected NiGe_0.5P_0.5/Ni₂Ge_0.5P_0.5 composite was investigated, and the result shows that it undergoes a conversion-type reaction, along with the generation of the Ni, Li₂Ni₁₂P₇, LiP, Li₃P, and Li_xGe phases. In addition, a topological conversion reaction mechanism between the Ni₂P-type structure and Li₂Ni₁₂P₇ was proposed. Moreover, a Ni–Ge–P₂/C composite was synthesized to improve the cycling performance of Ni–Ge–P₂. This method of regulating the electrochemical properties of materials by Ge substitution for P offers new insight into designing high-performance anodes.

Recently, the application of LiFePO₄ (LFP) batteries in electric vehicles has attracted extensive attention from researchers. This work presents a composite of LFP particles trapped in reduced graphene oxide (rGO) nanosheets obtained through the high-temperature reduction strategy. The obtained LiFePO₄/rGO composites indicate spherical morphology and uniform particles. As to the structure mode of the composite, LFP distributes in the interlayer structure of rGO, and the rGO evenly covers the surface of the particles. The LFP/rGO cathodes demonstrate a reversible specific capacity of 165 mA h g⁻¹ and high coulombic efficiency at 0.2 C, excellent rate capacity (up to 10 C), outstanding long-term cycling stability (98%) after 1000 cycles at 5 C. The combined high electron conductivity of the layered rGO coating and uniform LFP particles contribute to the remarkable electrochemical performance of the LFP/rGO composite. The unique LFP/rGO cathode provides a potential application in high-power lithium-ion batteries.

To construct a nonlinear fractional-order neural network reflecting the complex environment of the real world, this paper considers the common factors such as uncertainties, perturbations, and delays that affect the stability of the network system. In particular, not only does the activation function include multiple time delays, but the memristive connection weights also consider transmission delays. Stemming from the characteristics of neural networks, two different types of discontinuous controllers with state information and sign functions are devised to effectuate network synchronization objectives. Combining the finite-time convergence criterion and the theory of fractional-order calculus, Mittag-Leffler synchronization conditions for fractional-order multi-delayed memristive neural networks (FMMNNs) are derived, and the upper bound of the setting time can be confirmed. Unlike previous jobs, this article focuses on applying different inequality techniques in the synchronous analysis process, rather than comparison principles to manage the multi-delay effects. In addition, this study removes the restrictive requirement that the activation function has a zero value at the switching jumps, and the discontinuous control protocol in this paper makes the networks achieve synchronization over a finite time, with some advantages in terms of the convergence speed.

Lithium (Li) metal is perceived as the “holy grail” of anodes for secondary batteries due to its innate merits. Regrettably, the commercial application of Li metal anodes (LMAs) has been hampered by problems derived from the uncontrollable growth of Li dendrites, which could result in formation of short-circuits, thereby leading to fatal safety accidents. Here, a three-dimensional lithiophilic gold (Au)-coated copper (Cu) pentagonal pyramid array (Au@CuPPA) is constructed on planar Cu foil via electrodeposition followed by a chemical reduction method. Owing to the features of the lithiophilic layer and 3D porous structure, the proposed Au@CuPPA can not only facilitate Li-ion migration and charge transfer, but also effectively diminish the nucleation overpotential. Consequently, an even and steady Li plating/stripping process for up to 460 h and with a charge capacity of 3 mAh cm⁻² is accomplished by using the Au@CuPPA current collector. The Li@Au@CuPPA|LiFePO₄ full cell achieves a high Coulombic efficiency (CE) of 99.4% for 150 cycles at 0.5 C with a capacity retention of 92.4%.

A series of epoxy vitrimers (EVs) with enhanced glass transition temperatures (T_gs) were synthesized by curing epoxy resin E51 with different ratios of phthalic anhydride and sebacic acid as curing agents, and 1,5,7-triazabicyclic [4.4.0] dece-5-ene as a transesterification catalyst, and their curing dynamics, rheological properties, mechanical properties, and thermal stability were comprehensively investigated. By adjusting the molar ratio of the anhydride to the carboxylic acid in the curing agent, the T_gs of the EVs increased from 79 to 143 °C with the increase in the anhydride content. In particular, the material EV-5.5 with a high usable T_g of 98 °C could undergo stress relaxation through the transesterification reaction when exposed to high temperatures (160 to 200 °C), and the correlation between the relaxation time and temperature follows the Arrhenius equation. Moreover, EV-5.5 exhibited elastomeric behavior, where brittle fractures occurred before yielding, which demonstrated a tensile strength of 52 MPa. EV-5.5 also exhibited good thermal stability with a decomposition temperature (T_d5) of 322 °C. This study introduces new possibilities for practical applications of thermoset epoxy resins under special environmental conditions.