Low-Temperature Synthesis of Amorphous FePO4@rGO Composites for Cost-Effective Sodium-Ion Batteries

Research Progress of Electrolytes and Electrodes for Lithium- and Sodium-Ion Batteries at Extreme Temperatures

Lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) have recently received considerable attention in electrical energy storage (EES) systems due to their sustainability, high energy density, and superior energy conversion efficiency. However, with the expansion of energy storage application scenarios, the ability of batteries to operate under extreme conditions, especially low and high temperatures, is becoming increasingly important. Therefore, extending the operating temperature of electrochemically stable and safe LIBs and SIBs has become a critical research topic. In this review, the failure mechanism of batteries under extreme conditions and at the same time the problems faced by LIBs and SIBs in electrolyte and electrode materials are discussed, and various targeted optimization strategies are proposed. Additionally, the performance of LIBs and SIBs in such environments is compared, drawing an instructive understanding. Finally, a summary and perspective are presented for improving the battery electrochemical performance at low and high temperatures, respectively. Overall, this review aims to provide design guidelines for future LIBs and SIBs with high performance under extreme conditions.

High-Value Resource Utilization of Steel Waste to Prepare Uniform Micronano LiFePO4/C Cathode Material

Steel slag is a promising secondary resource necessitating recycling and high-value utilization. This study innovatively converted steel slag into micronano FePO4 and well-performing LiFePO4/C through a selective two-step leaching process followed by fast coprecipitation in HMCRR under superior mass transfer, and a subsequent in situ carbothermal reduction afterward, thereby realizing a waste-to-resource conversion pathway. Besides, a metal leaching mechanism was proposed based on comprehensive slag composition analysis, affirming the process selectivity. Thermomechanical analysis for precipitation underscored the importance of controlling reaction pH to prevent the formation of impure sediments. Leveraging efficient leaching and superior mass transfer during precursor preparation, the further-made carbon-coated LiFePO4/C derived from steel slag exhibited favorable morphology and enhanced discharge capacity, especially at high rates, owing to fast ion diffusion kinetics, minimized Li+ migration distance, and improved structure stability. Notably, the discharge capacity could reach 167.44, 153.56, and 119.62 mAh/g at 0.1, 1, and 10 C, respectively.

Amorphous Materials for Lithium-Ion and Post-Lithium-Ion Batteries

Lithium-ion and post-lithium-ion batteries are important components for building sustainable energy systems. They usually consist of a cathode, an anode, an electrolyte, and a separator. Recently, the use of solid-state materials as electrolytes has received extensive attention. The solid-state electrolyte materials (as well as the electrode materials) have traditionally been overwhelmingly crystalline materials, but amorphous (disordered) materials are gradually emerging as important alternatives because they can increase the number of ion storage sites and diffusion channels, enhance solid-state ion diffusion, tolerate more severe volume changes, and improve reaction activity. To develop superior amorphous battery materials, researchers have conducted a variety of experiments and theoretical simulations. This review highlights the recent advances in using amorphous materials (AMs) for fabricating lithium-ion and post-lithium-ion batteries, focusing on the correlation between material structure and properties (e.g., electrochemical, mechanical, chemical, and thermal ones).  We  review both the conventional and the emerging characterization methods for analyzing AMs and present the roles of disorder in influencing the performances of various batteries such as those based on lithium, sodium, potassium, and zinc. Finally,  we  describe the challenges and perspectives for commercializing rechargeable AMs-based batteries.

Nonenzymatic Sweat Wearable Uric Acid Sensor Based on N-Doped Reduced Graphene Oxide/Au Dual Aerogels

Sweat wearable sensors enable noninvasive and real-time metabolite monitoring in human health management but lack accuracy and wearable applicability. The rational design of sensing electrode materials will be critical yet challenging. Herein, we report a dual aerogel-based nonenzymatic wearable sensor for the sensitive and selective detection of uric acid (UA) in human sweat. The three-dimensional porous dual-structural aerogels composed of Au nanowires and N-doped graphene nanosheets (noted as N-rGO/Au DAs) provide a large active surface, abundant access to the target, rapid electron transfer pathways, and a high intrinsic activity. Thus, a direct UA electro-oxidation is demonstrated at the N-rGO/Au DAs with a much higher activity than those at the individual gels (i.e., Au and N-rGO). Moreover, the resulting sensing chip displays high performance with a good anti-interfering ability, long-term stability, and excellent flexibility toward the UA detection. With the assistance of a wireless circuit, a wearable sensor is successfully applied in the real-time UA monitoring on human skin. The obtained result is comparable to that evaluated by high-performance liquid chromatography. This dual aerogel-based nonenzymatic biosensing platform not only holds considerable promise for the reliable sweat metabolite monitoring but also opens an avenue for metal-based aerogels as flexible electrodes in wearable sensing.