Silicon (Si) has emerged as a potent anode material for lithium-ion batteries (LIBs), but faces challenges like low electrical conductivity and significant volume changes during lithiation/delithiation, leading to material pulverization and capacity degradation. Recent research on nanostructured Si aims to mitigate volume expansion and enhance electrochemical performance, yet still grapples with issues like pulverization, unstable solid electrolyte interface (SEI) growth, and interparticle resistance. This review delves into innovative strategies for optimizing Si anodes’ electrochemical performance via structural engineering, focusing on the synthesis of Si/C composites, engineering multidimensional nanostructures, and applying non-carbonaceous coatings. Forming a stable SEI is vital to prevent electrolyte decomposition and enhance Li⁺ transport, thereby stabilizing the Si anode interface and boosting cycling Coulombic efficiency. We also examine groundbreaking advancements such as self-healing polymers and advanced prelithiation methods to improve initial Coulombic efficiency and combat capacity loss. Our review uniquely provides a detailed examination of these strategies in real-world applications, moving beyond theoretical discussions. It offers a critical analysis of these approaches in terms of performance enhancement, scalability, and commercial feasibility. In conclusion, this review presents a comprehensive view and a forward-looking perspective on designing robust, high-performance Si-based anodes the next generation of LIBs.

The deployment of direct methanol fuel cells requires engineering cost-effective and durable electrocatalysts for the methanol oxidation reaction (MOR). As an alternative to noble metals, Ni-based alloys have shown excellent performance and good stability toward the MOR. Herein, we present a series of Ni_3−xCo_xSn₂ colloidal nanoparticles (NPs) with composition tuned over the entire Ni/Co range (0 ≤ x ≤ 3). We demonstrate electrodes based on these ternary NPs to provide improved catalytic performance toward the MOR in an alkaline medium when compared with binary Ni₃Sn₂ NPs. A preliminary composition optimization resulted in Ni_2.5Co_0.5Sn₂ NP-based electrodes exhibiting extraordinary mass current densities, up to 1050 mA mg⁻¹, at 0.6 V vs. Hg/HgO in 1.0 M KOH containing 1.0 M methanol. This current density was about two-fold higher than that of Ni₃Sn₂ electrodes (563 mA mg⁻¹). The excellent performance obtained with the substitution of small amounts of Ni by Co was concomitant with an increase of the surface coverage of active species and an enhancement of the diffusivity of the reaction limiting species. Additionally, saturation of the catalytic activity at higher methanol concentrations was measured for Ni_3−xCo_xSn₂ NP-based electrodes containing a small amount of Co when compared with binary Ni₃Sn₂ NPs. While the electrode stability was improved with respect to elemental Ni NP-based electrodes, the introduction of small amounts of Co slightly decreased the cycling performance. Additionally, Sn, a key element to improve stability with respect to elemental Ni NPs, was observed to slowly dissolve in the presence of KOH. Density functional theory calculations on metal alloy surfaces showed the incorporation of Co within the Ni₃Sn₂ structure to provide more effective sites for CO and CH₃OH adsorption. However, the relatively lower stability could not be related to CO or CH₃OH poisoning.

Transition metal phosphides have great potential to optimize a number of functionalities in several energy conversion and storage applications, particularly when nanostructured or in nanoparticle form. However, the synthesis of transition metal phosphide nanoparticles and its scalability is often limited by the toxicity, air sensitivity and high cost of the reagents used. We present here a simple, scalable and cost-effective ‘heating up’ procedure to produce metal phosphides using inexpensive, low-toxicity and air-stable triphenyl phosphite as source of phosphorous and chlorides as metal precursors. This procedure allows the synthesis of a variety of phosphide nanoparticles, including phosphides of Ni, Co and Cu. The use of carbonyl metal precursors further allowed the synthesis of Fe₂P and MoP nanoparticles. The fact that minor modifications in the experimental parameters allowed producing nanoparticles with different compositions and even to tune their size and shape, shows the high potential and versatility of the triphenyl phosphite precursor and the presented method. We also detail here a methodology to displace organic ligands from the surface of phosphide nanoparticles, which is a key step towards their application in energy conversion and storage systems.