This review explores the structural characteristics of LiFe_1-yMn_yPO₄ (LFMP) (0 < y < 1) and focuses on the redox evolution of Mn and Fe during charge-discharge processes, the kinetics of lithiation reactions, and the impact of lattice defects on performance. These insights are crucial for developing high-performance lithium-ion batteries. LFMP displays a variety of microstructural morphologies, and strategies such as ion doping and carbon coating are pivotal for enhancing its performance. With ongoing technological advancements, the industrialization of LFMP is gaining momentum. It is anticipated that LFMP will achieve commercial application shortly, which is expected to drive the advancement of battery recycling and technology upgrading.

The oxygen reduction reaction (ORR) is a pivotal process in electrochemical energy systems such as fuel cells and metal-air batteries. Recent advancements have highlighted the single-atom metal-nitrogen-carbon (M-N-C) catalysts for their exceptional ORR electrocatalytic performance. However, further exploration is needed for the optimization methods of single atomic active sites. Significantly, the modulation of coordination environment emerges as a pivotal technique for the enhancement of M-N-C catalysts, while extending this modulation beyond the first coordination shell has ignited substantial investigation. This review delves into the frontier of M-N-C optimization by transcending the first coordination shell, presenting a comprehensive analysis of innovative strategies that modulate the electronic structure and reactivity of MN₄ sites. The primary focus lies in three regulation approaches: regulating atomic entities, introducing metallic species and tailoring non-metallic modulators. These strategies are scrutinized for their ability to fine-tune the ORR activity and stability at the atomic level. By providing a clearer trajectory for future research, this review should be able to inspire novel designs of high-performance M-N-C ORR catalysts.

Protonic ceramic fuel cells (PCFCs) are regarded as efficient energy conversion devices for addressing the challenges of carbon neutrality, which can directly convert the chemical fuel energy into electricity at reduced operating temperatures below 700 °C. However, the insufficient strength and immature preparation processes of PCFCs limit their practical application. In this work, the novel anode-supported microtubular PCFCs with a tube diameter of less than 5 mm were successfully prepared by extrusion technology combined with a dip-coating method. The newly developed BaZr_0.4Ce_0.4Y_0.1Gd_0.1O_3-δ (BZCYG4411) proton-conducting electrolyte was synthesized using an extremely simple and efficient one-step solid-state reaction method, showing comparable electrical conductivity with BaZr_0.4Ce_0.4Y_0.1Yb_0.1O_3-δ (BZCYYb4411) and BaZr_0.1Ce_0.7Y_0.1Yb_0.1O_3-δ (BZCYYb1711) electrolytes, as well as excellent chemical stability. The single cell with Ba₂Sc_0.1Nb_0.1Co_1.5Fe_0.3O_6-δ (BSNCF) cathode exhibited a high peak power density of 906.86 mW cm^-2 at 700 °C. Additionally, this microtubular PCFC demonstrated excellent stability after about 103 h durability test at a constant current of 0.5 A cm^-2 at 650 °C. This study provides a highly efficient and simplified technology for fabricating high-performance and durable anode-supported microtubular PCFCs.

Nanoporous activated carbons derived from bio-waste are gaining consideration due to their exceptional potential for energy storage and CO₂ adsorption. Herein, we put forward a straightforward, low-cost method for preparing a highly efficient nanoporous biocarbon from ginger using solid-state activation approach. Ginger was pyrolyzed at various temperatures before activating using different amounts of KOH as an activator to produce nanoporous biocarbon. The prepared samples possess high specific surface areas and large pore volumes. By simply adjusting the pyrolysis temperature, the microporosity and surface oxygen functionalities can be finely tuned. The best sample exhibits a high Brunauer-Emmett-Teller-specific surface area of 2,330 m²/g and a large pore volume of 1.10 cm³/g and offers excellent specific capacitance of 244 and 119 F/g when tested in a three-electrode and two-electrode, at a current density of 0.5 A/g. Additionally, the optimized material demonstrates a high CO₂ uptake capacity of 4.87 mmol/g at ambient pressure and 25.8 mmol/g at 0 °C and 30 bar. These interesting adsorption and energy storage performances of the nanoporous biocarbon underscore the potential of converting food waste into high-performance CO₂ adsorbents and supercapacitors.

The process of gasification is well-known; however, to this day, the applications of such facilities, especially off-grid small-scale units for direct electricity and char production, are scarce. In this study, an off-grid fixed bed downdraft gasification unit is studied from the gaseous/solid product character perspective. This unit represents a possible solution for the emerging call for sustainable decentralised energy sources. Softwood chips were utilised in this study, and their conversion into synthetic gas (direct electricity supply) and solid biochar was observed and analysed. The results show promising values of synthetic gas for potential utilisation in different applications outside the direct combustion process, such as microbial syngas fermentation, with a lower heating value equal to 6.31 MJ·m^-3. It appears that during the steam activation process of biochar, both high-quality off-gas of more than 70%_vol. H₂ (excluding N₂) and activated carbon of a specific surface area of 565.87 m²·g^-1 can be collected. Further investigations have revealed specific degradation of chemical bonds and material morphology changes during steam gasification. The microporous structure and high specific surface area of the material make it an attractive material for further development as an adsorbent in sorption cooling devices. Therefore, the waste generated within the gasification process is minimised, and the potential of the obtained products will be valued in favour of the sustainability of the remote locations.

Improving the efficiency and safety of lithium-ion batteries (LIBs) with high-energy cathodes is crucial, yet challenging due to the limitations of commercial separators. Herein, we find that “giving” a portion of the Ni-rich LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) positive electrode to the Al₂O₃-coated polyethylene (PE) (PE/Al₂O₃) separator as an active and thick ceramic coating (> 10 µm) can more efficiently enhance the separator's wettability and thermal stability compared with the inert and thin (< 5 µm, typically 1~2 µm) Al₂O₃ coating. The NCM811 coating on the separator can take part in the electrochemical reaction and contribute capacity without increasing the cell dead weight. The NCM811-coated separator has a low thermal shrinkage of 0.8% at 160 °C and a high lithium-ion transfer number of 0.66. Notably, the NCM811-coated separator enhances electrochemical performance, delivering higher capacities compared to traditional PE and PE/Al₂O₃ separators. Furthermore, it effectively mitigates lithium dendrite formation, thereby bolstering LIB safety. Our findings demonstrate the potential of using active cathode materials as separator coatings to advance LIB technology with high-energy cathodes.

The development of high-entropy materials as active and durable catalysts for oxygen evolution reaction is important but challenging for hydrogen production from water electrolysis. In contrast to conventional synthesis strategies that usually involve high-temperature annealing, a novel poly(ethylene glycol)-barbituric acid deep eutectic solvent-assisted strategy was developed in this work to successfully synthesize high-entropy nitrides (HENs) (FeCoNiCuZn)N at a record low temperature of 473 K. Multiple analytical characterizations illustrate that dual entropic and enthalpic forces provided by the poly(ethylene glycol)-barbituric acid deep eutectic solvent play a critical role in the low-temperature synthesis of HENs. The prepared HENs have a microsphere structure consisting of five highly dispersed active metal (Fe, Co, Ni, Cu, and Zn) species, which are conducive to boosting oxygen evolution reaction performance in alkaline media, in terms of a low overpotential of 223 mV at 10 mA cm^-2 and sustained durability over 30 h at 400 mA cm^-2. This work paves the way for the fabrication of high-entropy materials with excellent electrocatalytic properties for future energy conversion and storage applications.

Recent advancements in light-driven interfacial water evaporation have underscored the potential of photothermal materials for producing clean water from various sources, including seawater, rivers, lakes, and wastewater. Despite these advancements, challenges in environmental management and energy conversion persist. The development of multifunctional photothermal materials and composites has addressed these challenges by integrating active species into water evaporation devices, thereby enhancing their performance and applicability. This review provides a thorough examination of recent progress in photothermal materials for water purification. It covers advances in material synthesis, optimization of evaporator configurations through various techniques, and their application in water treatment and clean water production. The discussion includes innovative heat management strategies designed to improve system efficiency. The review concludes by identifying current challenges and suggesting future research directions to advance the field of efficient water purification and clean water production.

Aqueous zinc-based batteries (ZIBs), characterized by their low cost, inherent safety, and environmental sustainability, represent a promising alternative for energy storage solutions in sustainable systems. Significant advancements have been made in developing high-performance cathode materials for aqueous ZIBs, which exhibit enhanced lifespan and energy density. However, challenges associated with zinc anodes, such as dendrite formation and side reactions, impede the practical application of ZIBs. This manuscript discusses the role of electrolyte additives in the Zn electrodeposition process and comprehensively describes strategies to enhance the anode stability through additive incorporation. It specifically focuses on the underlying mechanisms that regulate the solvation structure and the electrical double layer. Finally, the manuscript concludes with future perspectives on advancing Zn anode technology, aiming to provide guidelines for developing more robust Zn-based energy storage systems.

Mg alloys have frequently been studied as anodes for Mg-ion batteries due to their high specific capacity and low electrochemical potential. In the present study, we investigated the interfacial stability of MgBi alloy anodes with solid-state electrolytes. The bubble-like solid electrolyte interface (SEI) was observed between the MgBi alloy anode and Mg(BH₄)₂·1.9NH₃ solid-state electrolyte, leading to the unstable Mg stripping/plating on the MgBi alloy. Theoretical simulations suggest that the bubble-like SEI originates from the different Mg-ion dynamics on the eutectic region (e.g., Mg + Mg₃Bi₂ phases) and the Mg matrix. The addition of MgBr₂·2NH₃ nanoparticles in Mg(BH₄)₂·1.9NH₃ suppresses the formation of a bubble-like SEI through the etching effect of Br^- ions. Consequently, interfacial resistance is lowered and the interfacial stability is drastically enhanced, e.g., Mg stripping/plating for over 1,200 cycles at 0.1 mA cm^-2 with a low overpotential around 0.05 V.