Mg-Li Hybrid Batteries: The Combination of Fast Kinetics and Reduced Overpotential

It is imperative for the development of cost-effective and high-performance batteries. Currently, lithium-ion batteries still occupy most of the market. However, limited lithium (Li) resource and energy density retard their further development. The magnesium (Mg) metal has several significant advantages; those make it a viable alternative to Li as anode, including high volume specific capacity and dendrite-free plating during cycling and high abundance. The Mg-Li hybrid batteries can combine the advantages of Li ion and Mg metal to achieve fast electrode kinetics and smooth anode deposition morphology. This review summarizes recent progresses in cathode material design and anode interface modification for Mg-Li hybrid batteries. We aim to illustrate the contribution of Li+ to the electrochemical performance improvement at both cathode and anode sides and to provide inspiration for the future research in this field.

A Low-Crossover and Fast-Kinetics Thiolate Negolyte for Aqueous Redox Flow Batteries

Aqueous redox flow batteries (ARFBs) are a promising technology for large-scale energy storage. Developing high-capacity and long-cycle negolyte materials is one of major challenges for practical ARFBs. Inorganic polysulfide is promising for ARFBs owing to its low cost and high solubility. However, it suffers from severe crossover resulting in low coulombic efficiency and limited lifespan. Organosulfides are more resistant to crossover than polysulfides owing to their bulky structures, but they suffer from slow reaction kinetics. Herein, we report a thiolate negolyte prepared by an exchange reaction between a polysulfide and an organosulfide, preserving low crossover rate of the organosulfide and high reaction kinetics of the polysulfide. The thiolate denoted as 2-hydroxyethyl disulfide+potassium polysulfide (HEDS+K2S2) shows reduced crossover rate than K2S2, faster reaction kinetics than HEDS, and longer lifespan than both HEDS and K2S2. The 1.5 M HEDS+1.5 M K2S2 static cell demonstrated 96 Ah L-1negolyte over 100 and 200 cycles with a high coulombic efficiency of 99.2% and 99.6% at 15 and 25 mA cm-2, respectively. The 0.5 M HEDS+0.5 M K2S2 flow cell delivered a stable and high capacity of 30.7 Ah L-1negolyte over 400 cycles (691 h) at 20 mA cm-2. This study presents an effective strategy to enable low-crossover and fast-kinetics sulfur-based negolytes for advanced ARFBs.

Characterization of individual HIV-1 budding event using ultra-fast atomic force microscopy reveals a multiplexed role for VPS4

The assembly and budding of newly formed human immunodeficiency virus-1 (HIV-1) particles occur at the plasma membrane of infected cells. Whereas the molecular basis for viral budding has been studied extensively, investigation of its spatiotemporal characteristics has been limited by the small dimensions (< 100 nm) of HIV particles and the fast kinetics of the process (a few minutes from bud formation to virion release). Here we applied ultra-fast atomic force microscopy to achieve real-time visualization of individual HIV-1 budding events from wildtype (WT) cell lines as well as from mutated lines lacking vacuolar protein sorting-4 (VPS4) or visceral adipose tissue-1 protein (VTA1). Using single-particle analysis, we show that HIV-1 bud formation follows two kinetic pathways (fast and slow) with each composed of three distinct phases (growth, stationary, decay). Notably, approximately 30% of events did not result in viral release and were characterized by the formation of short (rather than tall) particles that slowly decayed back into the cell membrane. These non-productive events became more abundant in VPS4 knockout cell lines. Strikingly, the absence of VPS4B, rather than VPS4A, increased the production of short viral particles, suggesting a role for VPS4B in earlier stages of HIV-1 budding than traditionally thought.

On the Electrochemical Insertion of Mg2+in Na7V4(P2O7)4(PO4) and Na3V2(PO4)3 Host Materials

Next generation energy storage technologies need to be more sustainable and cheaper. Among Post-Li chemistries, Mg batteries are emerging as a possible alternative with desirable features like abundance of Mg on the Earth`s crust and a doubled volumetric capacity with respect to the current Li metal. However, research and development of Mg-batteries is still in its infancy stage and still many hurdles are to be understood and solved. For instance, cathode materials showing high capacities, operating at high potentials and with sufficient fast kinetics need to be designed and developed. Polyanionic materials are a class of sustainable and environmentally friendly materials that emerged as possible Mg2+ hosts. In this work the insertion of Mg cations inside the NASICON Na3V2(PO4)3 and, for the first time, in the mixed phosphate phase Na7V4(P2O7)4(PO4), is reported, structurally and electrochemically characterized.

Experimental Characterization of the Interaction between the N-Terminal SH3 Domain of Crkl and C3G

Crkl is a protein involved in the onset of several cancer pathologies that exerts its function only through its protein–protein interaction domains, a SH2 domain and two SH3 domains. SH3 domains are small protein interaction modules that mediate the binding and recognition of proline-rich sequences. One of the main physiological interactors of Crkl is C3G (also known as RAPGEF1), an interaction with key implications in regulating cellular growth and differentiation, cell morphogenesis and adhesion processes. Thus, understanding the interaction between Crkl and C3G is fundamental to gaining information about the molecular determinants of the several cancer pathologies in which these proteins are involved. In this paper, through a combination of fast kinetics at different experimental conditions and site-directed mutagenesis, we characterize the binding reaction between the N-SH3 domain of Crkl and a peptide mimicking a specific portion of C3G. Our results show a clear effect of pH on the stability of the complex, due to the protonation of negatively charged residues in the binding pocket of N-SH3. Our results are discussed under the light of previous work on SH3 domains.

Multicycle Performance of CaTiO3 Decorated CaO-Based CO2 Adsorbent Prepared by a Versatile Aerosol Assisted Self-Assembly Method

Calcium oxide (CaO) is a promising adsorbent to separate CO2 from flue gas. However, with cycling of carbonation/decarbonation at high temperature, the serious sintering problem causes its capture capacity to decrease dramatically. A CaTiO3-decorated CaO-based CO2 adsorbent was prepared by a continuous and simple aerosol-assisted self-assembly process in this work. Results indicated that CaTiO3 and CaO formed in the adsorbent, whereas CaO gradually showed a good crystalline structure with increased calcium loading. Owing to the high thermal stability of CaTiO3, it played a role in suppressing the sintering effect and maintaining repeated high-temperature carbonation and decarbonation processes. When the calcium and titanium ratio was 3, the CO2 capture capacity was as large as 7 mmol/g with fast kinetics. After 20 cycles under mild regeneration conditions (700 °C, N2), the performance of CO2 capture of CaTiO3-decorated CaO-based adsorbent nearly unchanged. Even after 10 cycles under severe regeneration conditions (920 °C, CO2), the performance of CO2 capture still remained nearly 70% compared to the first cycle. The addition of CaTiO3 induced good and firm CaO dispersion on its surface. Excellent kinetics and stability were evident.

Synthesis of Mesoporous γ-Alumina Support for Water Composite Sorbents for Low Temperature Sorption Heat Storage

The efficiency of thermochemical heat storage is crucially determined by the performance of the sorbent used, which includes a high sorption capacity and a low regeneration temperature. The thermochemical salt hydrate– γ-alumina composite sorbents are promising materials for this application but lack systematic study of the influence of γ-alumina structural properties on the final storage performance. In this study, mesoporous γ-Al2O3 supports were prepared by solvothermal and hydrothermal synthesis containing a block copolymer (F-127) surfactant to design thermochemical CaCl2 and LiCl composite water sorbents. Altering the solvent in the synthesis has a significant effect on the structural properties of the γ-Al2O3 mesostructure, which was monitored by powder XRD, nitrogen physisorption, and SEM. Solvothermal synthesis led to a formation of mesoporous γ-Al2O3 with higher specific surface area (213 m2/g) and pore volume (0.542 g/cm3) than hydrothermal synthesis (147 m2/g; 0.414 g/cm3). The highest maximal water sorption capacity (2.87 g/g) and heat storage density (5.17 GJ/m3) was determined for W-46-LiCl containing 15 wt% LiCl for space heating, while the best storage performance in the sense of fast kinetics of sorption, without sorption hysteresis, low desorption temperature, very good cycling stability, and energy storage density of 1.26 GJ/m3 was achieved by W-46-CaCl2.