2023 roadmap for potassium-ion batteries

The heavy reliance of lithium-ion batteries (LIBs) has caused rising concerns on the sustainability of lithium and transition metal and the ethic issue around mining practice. Developing alternative energy storage technologies beyond lithium has become a prominent slice of global energy research portfolio. The alternative technologies play a vital role in shaping the future landscape of energy storage, from electrified mobility to the efficient utilization of renewable energies and further to large-scale stationary energy storage. Potassium-ion batteries (PIBs) are a promising alternative given its chemical and economic benefits, making a strong competitor to LIBs and sodium-ion batteries for different applications. However, many are unknown regarding potassium storage processes in materials and how it differs from lithium and sodium and understanding of solid–liquid interfacial chemistry is massively insufficient in PIBs. Therefore, there remain outstanding issues to advance the commercial prospects of the PIB technology. This Roadmap highlights the up-to-date scientific and technological advances and the insights into solving challenging issues to accelerate the development of PIBs. We hope this Roadmap aids the wider PIB research community and provides a cross-referencing to other beyond lithium energy storage technologies in the fast-pacing research landscape

Tailoring biomass-derived carbon nanoarchitectures for high-performance supercapacitors

Supercapacitors are attracting intense scientific attention as they can bridge the energy-power gap between commercial batteries and electrolytic capacitors. High-surface area activated carbon remains the electrode material of choice for commercial systems due to the inherently lower cost relative to the more exotic alternatives such as graphene, carbon nanotubes, or their hybrids. However, activated carbon possesses an inferior electrochemical performance relative to these more open and electrically conductive structures. This limits its feasibility as electrodes for future high-performance devices. In this concept paper we summarized two case studies of creating unique biomass-derived carbons by preserving the precursors\u2019 intrinsic structure or transforming the precursor structure into graphene-like materials that actually demonstrate electrochemical performance on par with, or even better than, their much costlier alternatives.Peer reviewed: YesNRC publication: Ye

Does parental media mediation make a difference for adolescents? Evidence from an empirical cohort study of parent-adolescent dyads

Background and aims: Adolescents, who are undergoing brain changes, are vulnerable to many online risks in their use or overuse of digital technology. Parental media mediation (a set of practices parents use to guide children's media use and to reduce potential negative consequences of children from media) is considered an important way to help regulate and reduce adolescents' use or problematic use of digital media and protect them from online risks. However, previous studies have shown controversial results. These controversial results reflect a reproducibility crisis in psychological science due to selective reporting, selective analysis, and inadequate description of the conditions necessary to obtain results. Methods: To address this issue and reveal the authentic effect of parental media mediation strategies, this study presented the results of a specification curve analysis of 1176 combinations indicating the longitudinal effect of parental media mediation on adolescent smartphone use or problematic use. A total of 2154 parent-adolescent dyads (adolescents’ ages ranged from 9 to 18, the average age was 12.13 ± 2.20, and 817 of the adolescents were male) participated in two waves of measurements. Results: The results showed that of the 12 parental media mediations, joint parental use for learning had the greatest effect in reducing future smartphone use or problematic use among adolescents. Overall, none of the parental media mediations had a substantial effect in reducing future smartphone use or problematic use among adolescents. Discussion and conclusions: The ineffectiveness of parental media mediation poses a challenge for researchers, the public, and policy-makers. More exploration is needed in the search of effective parental media mediations for adolescents

Excellent energy\u2013power characteristics from a hybrid sodium ion capacitor based on identical carbon nanosheets in both electrodes

We created a hybrid Na ion capacitor (NIC) with a unique architecture and exceptional energy\u2013power characteristics. Both the anode and the cathode are based on peanut skin derived carbon nanosheets fabricated by simultaneous carbonization and activation or by carbonization alone. The tens of nanometer thick (down to 20 nm) \u2013 high surface area (up to 2070 m\ub2 g\u207b\ub9) nanosheets possesses a disordered structure for copious reversible binding of Na at the carbon defects. They are also hierarchically micro\u2013meso\u2013macro porous, allowing facile ion transport at high rates both through the pore-filling electrolyte and in the solid-state. When employed as sodium ion battery anode, the carbon shows a tremendous reversible (desodiation) capacity of 461 mA h g\u207b\ub9 at 100 mA g\u207b\ub9 and excellent rate capability, e.g. 107 mA h g\u207b\ub9 at 5 A g\u207b\ub9. The optimized NIC device displays highly favorable Ragone chart placement, e.g. 112 and 45 W h kg\u207b\ub9 at 67 and 12 000 W kg\u207b\ub9, retaining 85% of its capacity after 3000 cycles.Peer reviewed: YesNRC publication: Ye

High rate SnO2-Graphene Dual Aerogel anodes and their kinetics of lithiation and sodiation

We created a unique SnO2\u2013Graphene Dual Aerogel (SnO2/GDA) nanocomposite with exquisite lithium and sodium ion battery anode performance (LIB, NIB NAB SIB). In parallel we employed electrochemical methods to be the first to analyze the transition from kinetic control to diffusion control for the conversion reaction (SnO2+4Li++4e 12\u2194Sn+2Li2O) vs. for the alloying reaction (Sn+xLi++xe 12\u2194LixSn, x 644.4). The material displays a high reversible capacity (1299 mA h g 121 for Li at 0.1 A g 121, 448 mA h g 121 for Na at 0.05 A g 121), very good cycling life (148% after 450 cycles for Li, 82% from 20 to 200 cycles for Na), and superb rate capacity retention (450 mA h g 121 for Li at 25 A g 121, 184 mA h g 121 for Na at 1 Ag 121). In fact, these rate capabilities are among the most favorable reported in literature for each system.Peer reviewed: YesNRC publication: Ye

Nanocrystalline anatase TiO2: a new anode material for rechargeable sodium ion batteries

Anatase TiO2 nanocrystals were successfully employed as anodes for rechargeable Na-ion batteries for the first time. The mesoporous electrodes exhibited a highly stable reversible charge storage capacity of 3c150 mA h g-\ub9 over 100 cycles, and were able to withstand high rate cycling, fully recovering this capacity after being cycled at rates as high as 2 A g-\ub9.Peer reviewed: YesNRC publication: Ye

Significantly enhanced high permittivity and negative permittivity in Ag/ Al2O3/3D-BaTiO3/epoxy metacomposites with unique hierarchical heterogeneous microstructures

High dielectric permittivity materials are widely employed in various electronic devices. To satisfy the ongoing miniaturization of electronic devices, materials with further enhanced dielectric permittivities are strongly desired. In this work, a novel design of epoxy composites based on Ag/Al2O3/3D-BaTiO3 foams with hierarchical heterogeneous microstructures are prepared. It is found that, the spatial distribution of the Ag particles can be easily controlled via adjusting the Ag+/Al3+ mole ratios, yielding highly tailorable dielectric properties. When the Ag+/Al3+ mole ratios are low, the Ag particles are well isolated by surrounding Al2O3, yielding the formation of numerous equivalent micro-capacitors and substantially enhanced dielectric permittivity. Moreover, the dielectric permittivities of the composites increase with higher Ag+/Al3+ mole ratios. Consequently, a high dielectric permittivity of 160 @10 kHz, which is about 35 times that of the epoxy matrix, is achieved in the composite with a Ag+/Al3+ mole ratio of 1.8. Meanwhile, a low tangent of about 0.062 is maintained. As the Ag+/Al3+ mole ratio increases, the Ag particles become interconnected, forming Ag networks. Consequently, a plasma-like negative phenomenon which should be attributed to the plasma oscillation of free electrons in the percolative Ag networks, is observed. This work offers an effective route to design polymer composites with tailorable high permittivity and negative permittivity

Ultrahigh discharge efficiency and improved energy density in rationally designed bilayer polyetherimide-BaTiO3/P(VDF-HFP) composites

Polymer dielectric composites are of great interest as film capacitors that are widely used in pulsed power systems. For a long time, huge efforts have been devoted to achieving energy densities as high as possible to satisfy the miniaturization and high integration of electronic devices. However, the discharge efficiency which is particularly crucial to practical applications has gained little attention. With the target of achieving concurrently improved energy density and efficiency, a class of rationally designed bilayer composites consisting of a pure polyetherimide layer and a BaTiO3/P(VDF-HFP) composite layer were prepared. Interestingly, the bilayer composites exhibit ultrahigh discharge efficiencies eta (>95%) under external electric fields up to 400 kV mm(-1) which are much higher than most of the so far reported results (eta < 80%). Meanwhile, a low loss (tan delta < 0.05 @ 10 kHz) comparable to that of the pure polyetherimide is obtained. In addition, the bilayer composites show impressive improvements in breakdown strengths E-b, i.e., 285%, 363%, 366% and 567% for composites with 5 vol%, 10 vol%, 20 vol% and 40 vol% BaTiO3, compared to their single layer counterparts, resulting in obviously improved energy densities U-d. In particular, the bilayer composite with 10 vol% BaTiO3 displays the most prominent comprehensive energy storage performance, i.e., eta similar to 96.8% @ 450 kV mm(-1), U-d similar to 6 J cm(-3) @ 450 kV mm(-1), tan delta similar to 0.025 @ 10 kHz, and E-b similar to 483.18 kV mm(-1). The ultrahigh discharge efficiencies and high energy densities, along with low loss and breakdown strengths, make these bilayer composites ideal candidates for high-performance dielectric energy-storage capacitors

Sodiation vs. lithiation phase transformations in a high rate-high stability SnO2 in carbon nanocomposite

We employed a glucose mediated hydrothermal self-assembly method to create a SnO2-carbon nanocomposite with promising electrochemical performance as both a sodium and a lithium ion battery anode (NIBs NABs SIBs, LIBs), being among the best in terms of cyclability and rate capability when tested against Na. In parallel we provide a systematic side-by-side comparison of the sodiation vs. lithiation phase transformations in nano SnO2. The high surface area (338 m2 g-1) electrode is named C-SnO2, and consists of a continuous Li and Na active carbon frame with internally imbedded sub-5 nm SnO2 crystallites of high mass loading (60 wt%). The frame imparts excellent electrical conductivity to the electrode, allows for rapid diffusion of Na and Li ions, and carries the sodiation/lithiation stresses while preventing cycling-induced agglomeration of the individual crystals. C-SnO2 employed as a NIB anode displays a reversible capacity of 531 mA h g-1 (at 0.08 A g-1) with 81% capacity retention after 200 cycles, while capacities of 240, 188 and 133 mA h g-1 are achieved at the much higher rates of 1.3, 2.6 and 5 A g-1. As a LIB anode C-SnO2 maintains a capacity of 1367 mA h g-1 (at 0.5 A g-1) after 400 cycles, and 420 mA h g-1 at 10 A g-1. Combined TEM, XRD and XPS prove that the much lower capacity of SnO2 as a NIB anode is due to the kinetic difficulty of the Na-Sn alloying reaction to reach the terminal Na15Sn4 intermetallic, whereas for Li-Sn the Li22Sn5 intermetallic is readily formed at 0.01 V. Rather, with applied voltage a significant portion of the material effectively shuffles between SnO2 and \u3b2-Sn + NaO2. The conversion reaction proceeds differently in the two systems: LiO2 is reduced directly to SnO2 and Li, whereas the NaO2 to SnO2 reaction proceeds through an intermediate SnO phase.Peer reviewed: YesNRC publication: Ye

Cobalt Oxide-Carbon Nanosheet Nanoarchitecture as an Anode for High-Performance Lithium-Ion Battery

To improve the electrochemical performance of cobalt oxide owing to its inherent poor electrical conductivity and large volume expansion/contraction, Co₃O₄-carbon nanosheet hybrid nanoarchitectures were synthesized by a facile and scalable chemical process. However, it is still a challenge to control the size of Co₃O₄ particles down to ∼5 nm. Herein, we created nanosized cobalt oxide anchored 3D arrays of carbon nanosheets by the control of calcination condition. The uniformly dispersed Co₃O₄ nanocrystals on carbon nanosheets held a diameter down to ∼5 nm. When tested as anode materials for lithium-ion batteries, high lithium storage over 1200 mAh g^–1 is achieved, whereas high rate capability with capacity of about 390 mAh g^–1 at 10 A g^–1 is maintained through nanoscale diffusion distances and interconnected porous structure. After 500 cycles, the cobalt oxide-carbon nansheets hybrid display a reversible capacity of about 970 mAh g^–1 at 1 A g^–1. The synergistic effect between nanosized cobalt oxide and sheetlike interconnected carbon nanosheets lead to the greatly improved specific capacity and the initial Coulombic efficiency of the hybrids