Programmable DNA Interphase Layers for High-Performance Anode-Free Lithium Metal Batteries.

Anode-free lithium (Li) metal batteries are promising candidates for advanced energy storage, attributed to their appealing characteristics such as high energy density, low cost, and convenient production. However, their major challenges lie in the poor cycling and rate performance owing to the inferior reversibility and kinetics of Li plating and stripping, which significantly hinder their real-world applications. Here, it is demonstrated that deoxyribonucleic acid (DNA), the most important genetic material in nature, can serve as a highly programmable interphase layer for innovation of anode-free Li metal batteries. It is found that the abundant base pairs in DNA can contribute transient Li-N bonds that facilitate homogeneous Li+ flux, thus resulting in excellent Li plating/stripping kinetics and reversibility even at a harsh areal current of 15 mA cm-2. The anode-free LiFePO4 full batteries based on an ultrathin (0.12 µm) and ultralight (≈0.01 mg cm-2) DNA interphase layer show high CEs (≈99.1%) over 400 cycles, corresponding to an increase of ≈186% compared with bare copper (Cu) foil. These results shed light on the excellent programmability of DNA as a new family of interphase materials for anode-free batteries, and provide a new paradigm for future battery innovation toward high programmability, high sustainability, and remarkable electrochemical performance.

A dynamically stable self-healable wire based on mechanical-electrical coupling.

The rise in wearable electronics has witnessed the advancement of self-healable wires, which are capable of recovering mechanical and electrical properties upon structural damage. However, their highly fluctuating electrical resistances in the range of hundreds to thousands of ohms under dynamic conditions such as bending, pressing, stretching and tremoring may seriously degrade the precision and continuity of the resulting electronic devices, thus severely hindering their wearable applications. Here, we report a new family of self-healable wires with high strengths and stable electrical conductivities under dynamic conditions, inspired by mechanical-electrical coupling of the myelinated axon in nature. Our self-healable wire based on mechanical-electrical coupling between the structural and conductive components has significantly improved the electrical stability under dynamic scenarios, enabling precise monitoring of human health status and daily activities, even in the case of limb tremors from simulated Parkinson's disease. Our mechanical-electrical coupling strategy opens a new avenue for the development of dynamically stable electrodes and devices toward real-world wearable applications.

A rechargeable Ca/Cl2 battery.

Rechargeable calcium (Ca) metal batteries are promising candidates for sustainable energy storage due to the abundance of Ca in Earth's crust and the advantageous theoretical capacity and voltage of these batteries. However, the development of practical Ca metal batteries has been severely hampered by the current cathode chemistries, which limit the available energy and power densities, as well as their insufficient capacity retention and low-temperature capability. Here, we describe the rechargeable Ca/Cl2 battery based on a reversible cathode redox reaction between CaCl2 and Cl2, which is enabled by the use of lithium difluoro(oxalate)borate as a key electrolyte mediator to facilitate the dissociation and distribution of Cl-based species and Ca2+. Our rechargeable Ca/Cl2 battery can deliver discharge voltages of 3 V and exhibits remarkable specific capacity (1000 mAh g-1) and rate capability (500 mA g-1). In addition, the excellent capacity retention (96.5% after 30 days) and low-temperature capability (down to 0 °C) allow us to overcome the long-standing bottleneck of rechargeable Ca metal batteries.

Unlocking Reversible Silicon Redox for High-Performing Chlorine Batteries.

Chlorine (Cl)-based batteries such as Li/Cl2 batteries are recognized as promising candidates for energy storage with low cost and high performance. However, the current use of Li metal anodes in Cl-based batteries has raised serious concerns regarding safety, cost, and production complexity. More importantly, the well-documented parasitic reactions between Li metal and Cl-based electrolytes require a large excess of Li metal, which inevitably sacrifices the electrochemical performance of the full cell. Therefore, it is crucial but challenging to establish new anode chemistry, particularly with electrochemical reversibility, for Cl-based batteries. Here we show, for the first time, reversible Si redox in Cl-based batteries through efficient electrolyte dilution and anode/electrolyte interface passivation using 1,2-dichloroethane and cyclized polyacrylonitrile as key mediators. Our Si anode chemistry enables significantly increased cycling stability and shelf lives compared with conventional Li metal anodes. It also avoids the use of a large excess of anode materials, thus enabling the first rechargeable Cl2 full battery with remarkable energy and power densities of 809 Wh kg-1 and 4,277 W kg-1 , respectively. The Si anode chemistry affords fast kinetics with remarkable rate capability and low-temperature electrochemical performance, indicating its great potential in practical applications.

Anode-Free Lithium Metal Batteries Based on an Ultrathin and Respirable Interphase Layer.

Anode-free lithium (Li) metal batteries are desirable candidates in pursuit of high-energy-density batteries. However, their poor cycling performances originated from the unsatisfactory reversibility of Li plating/stripping remains a grand challenge. Here we show a facile and scalable approach to produce high-performing anode-free Li metal batteries using a bioinspired and ultrathin (250 nm) interphase layer comprised of triethylamine germanate. The derived tertiary amine and Lix Ge alloy showed enhanced adsorption energy that significantly promoted Li-ion adsorption, nucleation and deposition, contributing to a reversible expansion/shrinkage process upon Li plating/stripping. Impressive Li plating/stripping Coulombic efficiencies (CEs) of ≈99.3 % were achieved for 250 cycles in Li/Cu cells. In addition, the anode-free LiFePO4 full batteries demonstrated maximal energy and power densities of 527 Wh kg-1 and 1554 W kg-1 , respectively, and remarkable cycling stability (over 250 cycles with an average CE of 99.4 %) at a practical areal capacity of ≈3 mAh cm-2 , the highest among state-of-the-art anode-free LiFePO4 batteries. Our ultrathin and respirable interphase layer presents a promising way to fully unlock large-scale production of anode-free batteries.

Unlocking Deep and Fast Potassium-Ion Storage through Phosphorus Heterostructure.

Potassium-ion battery represents a promising alternative of conventional lithium-ion batteries in sustainable and grid-scale energy storage. Among various anode materials, elemental phosphorus (P) has been actively pursued owing to the ideal natural abundance, theoretical capacity, and electrode potential. However, the sluggish redox kinetics of elemental P has hindered fast and deep potassiation process toward the formation of final potassiation product (K3 P), which leads to inferior reversible capacity and rate performance. Here, it is shown that rational design on black/red P heterostructure can significantly improve K-ion adsorption, injection and immigration, thus for the first time unlocking K3 P as the reversible potassiation product for elemental P anodes. Density functional theory calculations reveal the fast adsorption and diffusion kinetics of K-ion at the heterostructure interface, which delivers a highly reversible specific capacity of 923 mAh g-1 at 0.05 A g-1 , excellent rate capability (335 mAh g-1 at 1 A g-1 ), and cycling performance (83.3% capacity retention at 0.8 A g-1 after 300 cycles). These results can unlock other sluggish and irreversible battery chemistries toward sustainable and high-performing energy storage.

Comparison of the effect of transparent film retainer and Hawley retainer / 口腔疾病防治

@#Long-term stability is an important part of orthodontic treatment and wearing a retainer is one of the methods to keep stable after active orthodontic treatment. Transparent film retainer and Hawley retainer are two kinds of retainer usually used in clinical treatment. the previous one is easy to made, comfortable and beautiful to wear, easily damaged. Hawley retainer is relatively complex to made and in a large size. And it is durable and adjustable. However, there are differences between these retainers on the retaining effects in different types of malocclusion. In clinical treatment, according to the type of malocclusion, we choose the appropriate retainer to keep stable occlusal relationship after orthodontic treatment.

Exogenous trehalose largely alleviates ionic unbalance, ROS burst, and PCD occurrence induced by high salinity in Arabidopsis seedlings.

Trehalose (Tre) has been reported to play a critical role in plant response to salinity and the involved mechanisms remain to be investigated in detail. Here, the putative roles of Tre in regulation of ionic balance, cellular redox state, cell death were studied in Arabidopsis under high salt condition. Our results found that the salt-induced restrictions on both vegetative and reproductive growth in salt-stressed plants were largely alleviated by exogenous supply with Tre. The microprobe analysis of ionic dynamics in the leaf and stem of florescence highlighted the Tre ability to retain K and K/Na ratio in plant tissues to improve salt tolerance. The flow cytometry assay of cellular levels of reactive oxygen species and programmed cell death displayed that Tre was able to antagonized salt-induced damages in redox state and cell death and sucrose did not play the same role with Tre. By comparing ionic distribution in leaf and inflorescence stem (IS), we found that Tre was able to restrict Na transportation to IS from leaves since that the ratio of Na accumulation in leaves relative to IS was largely improved due to Tre. The marked decrease of Na ion and improved sucrose level in IS might account for the promoted floral growth when Tre was included in the saline solution. At the same time, endogenous soluble sugars and antioxidant enzyme activities in the salt-stressed plants were also elevated by Tre to counteract high salt stress. We concluded that Tre could improve Arabidopsis salt resistance with respect to biomass accumulation and floral transition in the means of regulating plant redox state, cell death, and ionic distribution.