Expandable Li Percolation Network: The Effects of Site Distortion in Cation-Disordered Rock-Salt Cathode Material.

Cation-disordered rock-salt (DRX) materials receive intensive attention as a new class of cathode candidates for high-capacity lithium-ion batteries (LIBs). Unlike traditional layered cathode materials, DRX materials have a three-dimensional (3D) percolation network for Li+ transportation. The disordered structure poses a grand challenge to a thorough understanding of the percolation network due to its multiscale complexity. In this work, we introduce the large supercell modeling for DRX material Li1.16Ti0.37Ni0.37Nb0.10O2 (LTNNO) via the reverse Monte Carlo (RMC) method combined with neutron total scattering. Through a quantitative statistical analysis of the material's local atomic environment, we experimentally verified the existence of short-range ordering (SRO) and uncovered an element-dependent behavior of transition metal (TM) site distortion. A displacement from the original octahedral site for Ti4+ cations is pervasive throughout the DRX lattice. Density functional theory (DFT) calculations revealed that site distortions quantified by the centroid offsets could alter the migration barrier for Li+ diffusion through the tetrahedral channels, which can expand the previously proposed theoretical percolating network of Li. The estimated accessible Li content is highly consistent with the observed charging capacity. The newly developed characterization method here uncovers the expandable nature of the Li percolation network in DRX materials, which may provide valuable guidelines for the design of superior DRX materials.

Domino Reactions Enabling Sulfur-Mediated Gradient Interphases for High-Energy Lithium Batteries.

Silicon (Si)-based anodes are currently considered a feasible solution to improve the energy density of lithium-ion batteries owing to their sufficient specific capacity and natural abundance. However, Si-based anodes exhibit low electric conductivities and large volume changes during cycling, which could easily trigger continuous breakdown/reparation of the as-formed solid-electrolyte-interphase (SEI) layer, seriously hampering their practical application in current battery technology. To control the chemoelectrochemical instability of the conventional SEI layer, we herein propose the introduction of elemental sulfur into nonaqueous electrolytes, aiming to build a sulfur-mediated gradient interphase (SMGI) layer on Si-based anodes. The SMGI layer is generated through the domino reactions (i.e., electrochemical cascade reactions) involving the electrochemical reductions of elemental sulfur followed by nucleophilic substitutions of fluoroethylene carbonate, which endows the corresponding SEI layer with strong elasticity and chemomechanical stability and enables rapid transportation of Li+ ions. Consequently, the prototype Si||LiNi0.8Co0.1Mn0.1O2 cells attain a high-energy density of 622.2 W h kg-1 and a capacity retention of 88.8% after 100 cycles. Unlike previous attempts based on sophisticated chemical modifications of electrolyte components, this study opens a new avenue in interphase design for long-lived and high-energy rechargeable batteries.

Designer Cathode Additive for Stable Interphases on High-Energy Anodes.

Rechargeable lithium-based batteries built with high-energy anode materials (e.g., silicon-based and silicon-derivative materials) are considered a feasible solution to satisfy the stringent requirements imposed by emerging markets, including electric vehicles and grid storage, due to their higher energy density compared to contemporary lithium-ion batteries. The robustness of the solid electrolyte interphase (SEI) layer on high-energy anodes is critical to achieve long-term and stable cycling performances of the batteries. Herein, we propose a new type of designer cathode additive (DCA), i.e., an ultrathin coating layer of elemental sulfur on the cathode, for the in situ formation of a thin and robust SEI layer on various types of high-energy anodes. The DCA elemental sulfur undergoes simultaneous oxidation and reduction paths, forming lithium alkyl sulfate (R-OSO2OLi) and poly(ethylene oxide) (PEO)-like polymers on the anode surface. The as-formed R-OSO2OLi/PEO-modified SEI layer has good lithium cation (Li+) permeability to facilitate fast ion transportation across the interphases and superior elasticity to adapt to large volume changes, which is particularly effective for improving the cycling efficiency of high-energy anodes (e.g., ca. 14-35% increase in capacity retention for the silicon-carbon composite (SiC) or silicon-tin alloy (Si-Sn)||LiFePO4 cells). The present work opens a new avenue toward the practical deployment of high-energy rechargeable lithium-based batteries.

Anion Donicity of Liquid Electrolytes for Lithium Carbon Fluoride Batteries.

The increasing demand for high-energy powers have greatly incentivized the development of lithium carbon fluoride (Li||CFx ) cells. Five kinds of non-aqueous liquid electrolytes with various kinds of lithium salts (LiX, X=PF6 - , TFSI- , BF4 - , ClO4 - , and CF3 SO3 - ) were comparatively studied. Intriguingly, the LiBF4 -based electrolyte show relatively moderate ionic conductivities; yet, the corresponding Li||CFx cells deliver the highest discharge capacities among them. A combination of morphological and compositional analyses of the discharge CFx cathode suggest that the moderate donicity of BF4 - anion is accountable for favoring the breakdown of C-F bonds, and subsequently forming crystalline lithium fluoride as the main discharge products. This work brings not only fresh understanding on the role of salt anions for Li||CFx cells, but also inspire the electrolyte design for other conversion-type (sulfur and/or organosulfur) cathode materials desired for high-energy applications.

Joint Cationic and Anionic Redox Chemistry for Advanced Mg Batteries.

Lack of appropriate cathodes severely restrains the development of high-energy Mg batteries. In this work, we proposed joint cationic and anionic redox chemistry of transition-metal (TM) sulfides as the most promising way out. A series of solid-solution pyrite FexCo1-xS2 (0 ≤ x ≤ 1) was specially designed, in which S 3p electrons pour into the d bands of Fe and Co, generating redox-active dimerized (S2)2-. The Fe0.5Co0.5S2 sample is highlighted to deliver a high specific energy of 240 Wh/kg at room temperature involving both cationic (Fe and Co) and anionic (S) redox. The highly delocalized electronic clouds in pyrite structures comfortably accommodate the charge of Mg2+, contributing to the fast kinetics and the superior cycling stability of the Fe0.5Co0.5S2. It is anticipated that the joint cationic and anionic redox chemistry proposed in this work would be the ultimate answer for designing high-energy cathodes for advanced Mg batteries.

Li-Rich Li2 [Ni0.8 Co0.1 Mn0.1 ]O2 for Anode-Free Lithium Metal Batteries.

Anode-free lithium metal batteries can maximize the energy density at the cell level. However, without the Li compensation from the anode side, it faces much more challenging to achieve a long cycling life with a competitive energy density than Li metal-based batteries. Here, we prolong the lifespan of an anode-free Li metal battery by introducing Li-rich Li2 [Ni0.8 Co0.1 Mn0.1 ]O2 into the cathode as a Li-ions extender. The Li2 [Ni0.8 Co0.1 Mn0.1 ]O2 can release a large amount of Li-ions during the first charging process to supplement the Li loss in the anode, then convert into NCM811, thus extending the lifespan of the battery without the introduction of inactive elements. By the benefit of Li-rich cathode and high reversibility of Li metal on Cu foil, the anode-free pouch cells enable to achieve 447 Wh kg-1 energy density and 84 % capacity retention after 100 cycles in the condition of limited electrolyte addition (E/C ratio of 2 g Ah-1 ).

Ultralight Electrolyte for High-Energy Lithium-Sulfur Pouch Cells.

The high weight fraction of the electrolyte in lithium-sulfur (Li-S) full cell is the primary reason its specific energy is much below expectations. Thus far, it is still a challenge to reduce the electrolyte volume of Li-S batteries owing to their high cathode porosity and electrolyte depletion from the Li metal anode. Herein, we propose an ultralight electrolyte (0.83 g mL-1 ) by introducing a weakly-coordinating and Li-compatible monoether, which greatly reduces the weight fraction of electrolyte within the whole cell and also enables Li-S pouch cell functionality under lean-electrolyte conditions. Compared to Li-S batteries using conventional counterparts (≈1.2 g mL-1 ), the Li-S pouch cells equipped with our ultralight electrolyte could achieve an ultralow electrolyte weight/capacity ratio (E/C) of 2.2 g Ah-1 and realize a 19.2 % improvement in specific energy (from 329.9 to 393.4 Wh kg-1 ) under E/S=3.0 µL mg-1 . Moreover, more than 20 % improvement in specific energy could be achieved using our ultralight electrolyte at various E/S ratios.

From Solid-Solution Electrodes and the Rocking-Chair Concept to Today's Batteries.

Lithium-ion batteries (LIBs) have become ubiquitous power sources for small electronic devices, electric vehicles, and stationary energy storage systems. Despite the success of LIBs which is acknowledged by their increasing commodity market, the historical evolution of the chemistry behind the LIB technologies is laden with obstacles and yet to be unambiguously documented. This Viewpoint outlines chronologically the most essential findings related to today's LIBs, including commercial electrode and electrolyte materials, but furthermore also depicts how the today popular and widely emerging solid-state batteries were instrumental at very early stages in the development of LIBs.

Slope-Dominated Carbon Anode with High Specific Capacity and Superior Rate Capability for High Safety Na-Ion Batteries.

The comprehensive performance of carbon anodes for Na-ion batteries (NIBs) is largely restricted by their inferior rate capability and safety issues. Herein, a slope-dominated carbon anode is achieved at a low temperature of 800 °C, which delivers a high reversible capacity of 263 mA h g-1 at 0.15C with an impressive initial Coulombic efficiency (ICE) of 80 %. When paired with the NaNi1/3 Fe1/3 Mn1/3 O2 cathode, the reversible capacity at 6C is still 75 % of that at 0.15C, and 73 % of the capacity is retained after 1000 cycles at 3C. The enhanced Na storage performance could be attributed to the unique microstructure with randomly oriented short carbon layers and the relatively higher defect concentration. Given its robustness, such a low-temperature carbonization strategy could also be applicable to other precursors and provide a new opportunity to design slope-dominated carbon anodes for high safety, low-cost NIBs with excellent ICE and superior rate capability.

Stabilizing the Oxygen Lattice and Reversible Oxygen Redox Chemistry through Structural Dimensionality in Lithium-Rich Cathode Oxides.

Lattice-oxygen redox (l-OR) has become an essential companion to the traditional transition-metal (TM) redox charge compensation to achieve high capacity in Li-rich cathode oxides. However, the understanding of l-OR chemistry remains elusive, and a critical question is the structural effect on the stability of l-OR reactions. Herein, the coupling between l-OR and structure dimensionality is studied. We reveal that the evolution of the oxygen-lattice structure upon l-OR in Li-rich TM oxides which have a three-dimensional (3D)-disordered cation framework is relatively stable, which is in direct contrast to the clearly distorted oxygen-lattice framework in Li-rich oxides which have a two-dimensional (2D)/3D-ordered cation structure. Our results highlight the role of structure dimensionality in stabilizing the oxygen lattice in reversible l-OR, which broadens the horizon for designing high-energy-density Li-rich cathode oxides with stable l-OR chemistry.

Single Lithium-Ion Conducting Polymer Electrolytes Based on a Super-Delocalized Polyanion.

A novel single lithium-ion (Li-ion) conducting polymer electrolyte is presented that is composed of the lithium salt of a polyanion, poly[(4-styrenesulfonyl)(trifluoromethyl(S-trifluoromethylsulfonylimino)sulfonyl)imide] (PSsTFSI(-)), and high-molecular-weight poly(ethylene oxide) (PEO). The neat LiPSsTFSI ionomer displays a low glass-transition temperature (44.3 °C; that is, strongly plasticizing effect). The complex of LiPSsTFSI/PEO exhibits a high Li-ion transference number (tLi (+) =0.91) and is thermally stable up to 300 °C. Meanwhile, it exhibits a Li-ion conductivity as high as 1.35×10(-4)  S cm(-1) at 90 °C, which is comparable to that for the classic ambipolar LiTFSI/PEO SPEs at the same temperature. These outstanding properties of the LiPSsTFSI/PEO blended polymer electrolyte would make it promising as solid polymer electrolytes for Li batteries.

DHAFormer: Dual-channel hybrid attention network with transformer for polyp segmentation.

The accurate early diagnosis of colorectal cancer significantly relies on the precise segmentation of polyps in medical images. Current convolution-based and transformer-based segmentation methods show promise but still struggle with the varied sizes and shapes of polyps and the often low contrast between polyps and their background. This research introduces an innovative approach to confronting the aforementioned challenges by proposing a Dual-Channel Hybrid Attention Network with Transformer (DHAFormer). Our proposed framework features a multi-scale channel fusion module, which excels at recognizing polyps across a spectrum of sizes and shapes. Additionally, the framework's dual-channel hybrid attention mechanism is innovatively conceived to reduce background interference and improve the foreground representation of polyp features by integrating local and global information. The DHAFormer demonstrates significant improvements in the task of polyp segmentation compared to currently established methodologies.

Designer Lithium Reservoirs for Ultralong Life Lithium Batteries for Grid Storage.

The minimization of irreversible active lithium loss stands as a pivotal concern in rechargeable lithium batteries, particularly in the context of grid-storage applications, where achieving the utmost energy density over prolonged cycling is imperative to meet stringent demands, notably in terms of life cost. Departing from conventional methodologies advocating electrode prelithiation and/or electrolyte additives, a new paradigm is proposed here: the integration of a designer lithium reservoir (DLR) featuring lithium orthosilicate (Li4SiO4) and elemental sulfur. This approach concurrently addresses active lithium consumption through solid electrolyte interphase (SEI) formation and mitigates minor yet continuous parasitic reactions at the electrode/electrolyte interface during extended cycling. The remarkable synergy between the Li-ion conductive Li4SiO4 and the SEI-favorable elemental sulfur enables customizable compensation kinetics for active lithium loss throughout continuous cycling. The introduction of a minute quantity of DLR (3 wt% Li4SiO4@S) yields outstanding cycling stability in a prototype pouch cell (graphite||LiFePO4) with an ampere-hour-level capacity (≈2.3 Ah), demonstrating remarkable capacity retention (≈95%) even after 3000 cycles. This utilization of a DLR is poised to expedite the development of enduring lithium batteries for grid-storage applications and stimulate the design of practical, implantable rechargeable batteries based on related cell chemistries.

High-Entropy Microdomain Interlocking Polymer Electrolytes for Advanced All-Solid-State Battery Chemistries.

All-solid-state polymer electrolytes (ASPEs) with excellent processivity are considered one of the most forward-looking materials for large-scale industrialization. However, the contradiction between improving the mechanical strength and accelerating the ionic migration of ASPEs has always been difficult to reconcile. Herein, a rational concept is raised of high-entropy microdomain interlocking ASPEs (HEMI-ASPEs), inspired by entropic elasticity well-known in polymer and biochemical sciences, by introducing newly designed multifunctional ABC miktoarm star terpolymers into polyethylene oxide for the first time. The tailor-made HEMI-ASPEs possess multifunctional polymer chains, which induce themselves to assemble into micro- and nanoscale dynamic interlocking networks with high topological structure entropy. HEMI-ASPEs achieve excellent toughness, considerable ionic conductivity, an appreciable lithium transference number (0.63), and desirable thermal stability (Td  > 400 °C) for all-solid-state lithium metal batteries. The Li|HEMI-ASPE-Li|Li symmetrical cell shows a stable Li plating/stripping performance over 4000 h, and a LiFePO4 |HEMI-ASPE-Li|Li full cell exhibits a high capacity retention (≈96%) after 300 cycles. This work contributes an innovative design concept introducing high-entropy supramolecular dynamic networks for ASPEs.

Volatile metabolomics reveals the characteristics of the unique flavor substances in oats.

Oats is a cereal well known for its high nutritional value and unique flavor. This study investigated the metabolomics data from oats, wheat, and barley using broadly targeted GC-MS metabonomic techniques. A total of 437 volatile organic compounds (VOCs) were identified, of which 414 were shared metabolites, with three metabolites unique to oats. Three hundred and seven differentially accumulated metabolites (DAMs) were screened from all the comparison groups, of which 27 metabolites were shared by oats and barley, and 121 shared by oats and wheat. Terpenoids and esters were the key metabolites determining the differences in flavor. A KEGG analysis indicated that the alpha-linolenic acid and phenylalanine pathways were the most significant metabolic pathways. The 42 DAMs found may be the main substances leading to the flavor differences between the different varieties. Overall, this study reveals the main reasons for the unique flavor of oats through metabolomic evidence.

Staphylococcus aureus induces mitophagy to promote its survival within bovine mammary epithelial cells.

Mitophagy occurs in a variety of pathogenic infections. However, the role of mitophagy in the intracellular survival of Staphylococcus aureus (S.aureus) within bovine mammary epithelial cells (BMECs) and which molecules specifically mediate the induction of mitophagy remains unclear. Therefore, this study aims to investigate the role and mechanism of mitophagy in the intracellular survival of S.aureus. Here, we reported that S.aureus induced complete mitophagy to promote its survival within BMECs. The further mechanistic study showed that S. aureus induced mitophagy by activating the p38-PINK1-Parkin signaling pathway. These findings expand our knowledge of the intracellular survival mechanism of S.aureus in the host and provide a desirable therapeutic strategy against S.aureus and other intracellular infections.

Electrolysis Process-Facilitated Engineering of Primary Particles of Cobalt-Free LiNiO2 for Improved Electrochemical Performance.

The particle morphology of LiNiO2 (LNO), the final product of Co-free high-Ni layered oxide cathode materials, must be engineered to prevent the degradation of electrochemical performance caused by the H2-H3 phase transition. Introducing a small amount of dopant oxides (Nb2O5 as an example) during the electrolysis synthesis of the Ni(OH)2 precursor facilitates the engineering of the primary particles of LNO, which is quick, simple, and inexpensive. In addition to the low concentration of Nb that entered the lattice structure, a combination of advanced characterizations indicates that the obtained LNO cathode material contains a high concentration of Nb in the primary particle boundaries in the form of lithium niobium oxide. This electrolysis method facilitated LNO (EMF-LNO) engineering successfully, reducing primary particle size and increasing particle packing density. Therefore, the EMF-LNO cathode material with engineered morphology exhibited increased mechanical strength and electrical contact, blocked electrolyte penetration during cycling, and reduced the H2-H3 phase transition effects.

Anion-enrichment interface enables high-voltage anode-free lithium metal batteries.

Aggressive chemistry involving Li metal anode (LMA) and high-voltage LiNi0.8Mn0.1Co0.1O2 (NCM811) cathode is deemed as a pragmatic approach to pursue the desperate 400 Wh kg-1. Yet, their implementation is plagued by low Coulombic efficiency and inferior cycling stability. Herein, we propose an optimally fluorinated linear carboxylic ester (ethyl 3,3,3-trifluoropropanoate, FEP) paired with weakly solvating fluoroethylene carbonate and dissociated lithium salts (LiBF4 and LiDFOB) to prepare a weakly solvating and dissociated electrolyte. An anion-enrichment interface prompts more anions' decomposition in the inner Helmholtz plane and higher reduction potential of anions. Consequently, the anion-derived interface chemistry contributes to the compact and columnar-structure Li deposits with a high CE of 98.7% and stable cycling of 4.6 V NCM811 and LiCoO2 cathode. Accordingly, industrial anode-free pouch cells under harsh testing conditions deliver a high energy of 442.5 Wh kg-1 with 80% capacity retention after 100 cycles.

A Better Choice to Achieve High Volumetric Energy Density: Anode-Free Lithium-Metal Batteries.

Volumetric energy density is a critical but easily neglected index of lithium-metal batteries (LMBs). Compared with gravimetric energy density, the volumetric energy density (VED) of LMBs is much more sensitive to the anode/cathode (A/C) ratio due to the low density of lithium (Li) metal and the volume expansion of the Li-metal anode owing to its pulverization during cycles. Anode-free LMBs (AF-LMBs) have high theoretical VED due to the absence of an anode and high retention with relatively low cell expansion. Because Li plating highly depends on the mother substrate, Li plating on copper (Cu) substrates is more reversible and denser than that on Li substrates during cycling, which is beneficial for maintaining high volumetric capacity and efficient Li utilization. Therefore, considering that excess Li must be strictly limited to achieve competitive energy density, AF-LMBs (with bare Cu foil as the anode current collector) for high-volumetric-density batteries are recommended.

Bilayer Halide Electrolytes for All-Inorganic Solid-State Lithium-Metal Batteries with Excellent Interfacial Compatibility.

Inorganic solid-state electrolytes (ISSEs) have been extensively researched as the critical component in all-solid-state lithium-metal batteries (ASSLMBs). Many ISSEs exhibit high ionic conductivities up to 10-3 S cm-1. However, most of them suffer from poor interfacial compatibility with electrodes, especially lithium-metal anodes, limiting their application in high-performance ASSLMBs. To achieve good interfacial compatibility with a high-voltage cathode and a lithium-metal anode simultaneously, we propose Li3InCl6/Li2OHCl bilayer halide ISSEs with complementary advantages. In addition to the improved interfacial compatibility, the Li3InCl6/Li2OHCl bilayer halide ISSEs exhibit good thermal stability up to 160 °C. The Li-symmetric cells with sandwich electrolytes Li2OHCl/Li3InCl6/Li2OHCl exhibit long cycling life of over 300 h and a high critical current density of over 0.6 mA cm-2 at 80 °C. Moreover, the all-inorganic solid-state lithium-metal batteries (AISSLMBs) LiFePO4-Li3InCl6/Li3InCl6/Li2OHCl/Li fabricated by a facile cold-press method exhibit good rate performance and long-term cycling stability that stably cycle for about 3000 h at 80 °C. This work presents a facile and cost-effective method to construct bilayer halide ISSEs, enabling the development of high-performance AISSLMBs with good interfacial compatibility and thermal stability.