Enhancing Anion-Selective Catalysis for Stable Lithium Metal Pouch Cells through Charge Separated COF Interlayer.

Regulating the composition of solid-electrolyte-interphase (SEI) is the key to construct high-energy density lithium metal batteries. Here we report a selective catalysis anionic decomposition strategy to achieve a lithium fluoride (LiF)-rich SEI for stable lithium metal batteries. To accomplish this, the tris(4-aminophenyl) amine-pyromeletic dianhydride covalent organic frameworks (TP-COF) was adopted as an interlayer on lithium metal anode. The strong donor-acceptor unit structure of TP-COF induces local charge separation, resulting in electron depletion and thus boosting its affinity to FSI-. The strong interaction between TP-COF and FSI- lowers the lowest unoccupied molecular orbital (LUMO) energy level of FSI-, accelerating the decomposition of FSI- and generating a stable LiF-rich SEI. This feature facilitates rapid Li+ transfer and suppresses dendritic Li growth. Notably, we demonstrate a 6.5 Ah LiNi0.8Co0.1Mn0.1O2|TP-COF@Li pouch cell with high energy density (473.4 Wh kg-1) and excellent cycling stability (97.4 %, 95 cycles) under lean electrolyte 1.39 g Ah-1, high areal capacity 5.7 mAh cm-2, and high current density 2.7 mA cm-2. Our selective catalysis strategy opens a promising avenue toward the practical applications of high energy-density rechargeable batteries.

[Pathway-focused correlation study of genome-wide methylation status with visual memory].

OBJECTIVE To explore the biological processes and pathways associated with memory function which may be regulated by gene promoter methylation. METHODS The genome-wide promoter methylation statuses in 9 healthy individuals were analyzed with a Multiplex HG18 CpG Promoter chip. Genes with promoter methylation statuses strongly correlated with both immediate and delayed visual memory function were preceded for pathway and physical interactions analysis. RESULTS Sixty nine genes have been correlated with both immediate and delayed visual memory functions. Twenty two pathways, with a Q-value of < 0.05, were identified by the pathway and physical interactions analysis, which included energy metabolism, axon guidance, tyrosine kinase activity, anterograde synaptic vesicle transport, and leukocyte migration and differentiation. CONCLUSION Pathways related with memory function may be regulated by DNA methylation.

Efficient Fabrication of Disordered Graphene with Improved Ion Accessibility, Ion Conductivity, and Density for High-Performance Compact Capacitive Energy Storage.

High-performance compact capacitive energy storage is vital for many modern application fields, including grid power buffers, electric vehicles, and portable electronics. However, achieving exceptional volumetric performance in supercapacitors is still challenging and requires effective fabrication of electrode films with high ion-accessible surface area and fast ion diffusion capability while simultaneously maintaining high density. Herein, a facile, efficient, and scalable method is developed for the fabrication of dense, porous, and disordered graphene through spark-induced disorderly opening of graphene stacks combined with mechanical compression. The obtained disordered graphene achieves a high density of 1.18 g cm-3, sixfold enhanced ion conductivity compared to common laminar graphene, and an ultrahigh volumetric capacitance of 297 F cm-3 in ionic liquid electrolyte. The fabricated stack cells deliver a volumetric energy density of 94.2 Wh L-1 and a power density of 13.7 kW L-1, representing a critical breakthrough in capacitive energy storage. Moreover, the proposed disordered graphene electrodes are assembled into ionogel-based all-solid-state pouch cells with high mechanical stability and multiple optional outputs, demonstrating great potential for flexible energy storage in practical applications.

Compact 3D Metal Collectors Enabled by Roll-to-Roll Nanoimprinting for Improving Capacitive Energy Storage.

Reducing the contact resistance between active materials and current collectors is of engineering importance for improving capacitive energy storage. 3D current collectors have shown extraordinary promise for reducing the contact resistance, however, there is a major obstacle of being bulky or inefficient fabrication before they become viable in practice. Here a roll-to-roll nanoimprinting method is demonstrated to deform flat aluminum foils into 3D current collectors with hierarchical microstructures by combining soft matter-enhanced plastic deformation and template-confined local surface nanocracks. The generated 3D current collectors are inserted by and interlocked with active electrode materials such as activated carbon, decreasing the contact resistance by at least one order of magnitude and quadrupling the specific capacitance at high current density of 30 A g-1 for commercial-level mass loading of 5 mg cm-2 . The 3D current collectors are so compact that they have a low volume percentage of 7.8% in the entire electrode film, resulting in energy and power density of 29.1 Wh L-1 and 12.8 kW L-1 , respectively, for stack cells in organic electrolyte. Furthermore, roll-to-roll nanoimprinting of metal microstructures is low-cost, high-throughput, and can be extended to other systems that involve the microstructured metal interface, such as batteries and thermal management.

Tuning the Mechanical and Electrical Properties of Porous Electrodes for Architecting 3D Microsupercapacitors with Batteries-Level Energy.

Microsupercapacitors (MSCs) are vital power sources for internet of things (IoTs) and miniaturized electronics. The performance of MSCs is often restricted by its low areal energy density, which is due to the low areal mass loading of active materials. Constructing thick planar microelectrode with fine structure and high aspect ratio is an efficient way to increase mass loading, but limited by the breakable nature of porous electrode materials. Here, it is found that the mechanical and electrical properties of porous electrodes, as well as their surface area utilization and internal ion diffusion pathway, can be synergistically tuned by infilling gel electrolyte into internal pores of porous electrode films. The tuned thick porous electrode films are robust enough to enable laser ablation of three dimensional (3D) microelectrodes for high mass loading and high aspect ratio. The areal capacitance of 3D microelectrodes is able to increase linearly with mass loading (or thickness) up to at least 13 mg cm-2  (or 260 µm) for a value of up to 4640 mF cm-2 based on active carbon. The 3D MSCs deliver areal energy density of 1318 µWh cm-2 , which is comparable to the best of Li-ion 3D microbatteries while exhibiting superior electrochemical and mechanical stability.

Scalable fabrication of high-performance micro-supercapacitors by embedding thick interdigital microelectrodes into microcavities.

Micro-supercapacitors (MSCs) with thick interdigital microelectrodes of carbon-based materials exhibit excellent electrochemical performance and hold tremendous promise for applications in microscale energy storage devices. Here, a scalable strategy to fabricate thick embedded multiwalled carbon nanotubes (MWCNTs) as interdigital microelectrodes for MSCs has been developed and investigated. To this end, sufficient MWNCT inks are firstly cast onto pre-patterned microcavity surfaces and then more MWCNT materials are embedded into the microcavities by rapid solvent evaporation. After removal of residual materials from the surfaces by a doctor-blading process, thick interdigital MWCNT microelectrodes with heights up to 190 µm are obtained. These embedded microelectrodes simplify the device structure and improve the mechanical flexibility by acting as both active materials and current collectors. Using interdigital microelectrodes with a width of 250 µm and an interspace of 50 µm, the fabricated MSCs exhibit outstanding electrochemical performance with a high capacitance of 19.5 mF cm-2 and an energy density of 2.48 µW h cm-2 at a power density of 24.7 µW cm-2. On the other hand, four light emitting diodes (LEDs) are successfully powered by three series of MSCs, indicating that MSCs can be connected in series and parallel to yield suitable operating voltages and currents for practical applications.