Bioaugmented ensiling of sweet sorghum with Pichia anomala and cellulase and improved enzymatic hydrolysis of silage via ball milling.

Sweet sorghum, as a seasonal energy crop, is rich in cellulose and hemicellulose that can be converted into biofuels. This work aims at investigating the effects of synergistic regulation of Pichia anomala and cellulase on ensiling quality and microbial community of sweet sorghum silages as a storage and pretreatment method. Furthermore, the combined pretreatment effects of ensiling and ball milling on sweet sorghum were evaluated by microstructure change and enzymatic hydrolysis. Based on membership function analysis, the combination of P. anomala and cellulase (PA + CE) significantly improved the silage quality by preserving organic components and promoting fermentation characteristics. The bioaugmented ensiling with PA + CE restructured the bacterial community by facilitating Lactobacillus and inhibiting undesired microorganisms by killer activity of P. anomala. The combined bioaugmented ensiling pretreatment with ball milling significantly increased the enzymatic hydrolysis efficiency (EHE) to 71%, accompanied by the increased specific surface area and decreased pore size/crystallinity of sweet sorghum. Moreover, the EHE after combined pretreatment was increased by 1.37 times compared with raw material. Hence, the combined pretreatment was demonstrated as a novel strategy to effectively enhance enzymatic hydrolysis of sweet sorghum.

A multifunctional composite hydrogel that sequentially modulates the process of bone healing and guides the repair of bone defects.

Calcium carbonate (CaCO3), which exhibits excellent biocompatibility and bioactivity, is a well-established bone filling material for bone defects. Here, we synthesized CaCO3microspheres (CMs) to use as an intelligent carrier to load bone morphogenetic protein-2 (BMP-2). Subsequently, drug-loaded CMs and catalase (CAT) were added to methacrylated gelatin (GelMA) hydrogels to prepare a composite hydrogel for differential release of the drugs. CAT inside hydrogels was released with a fast rate to eliminate H2O2and generate oxygen. Constant BMP-2 release from CMs induced rapid osteogenesis. Resultsin vitroindicated that the composite hydrogels efficiently reduced the level of intracellular reactive oxygen species, preventing cells from being injured by oxidative stress, promoting cell survival and proliferation, and enhancing osteogenesis. Furthermore, animal experiments demonstrated that the composite hydrogels were able to inhibit the inflammatory response, regulate macrophage polarization, and facilitate the healing of bone defects. These findings indicate that a multi-pronged strategy is greatly expected to promote the bone healing by modulating pathological microenvironments.

Establishment of a risk prediction model for residual low back pain in thoracolumbar osteoporotic vertebral compression fractures after percutaneous kyphoplasty.

OBJECTIVE: This study aims to identify potential independent risk factors for residual low back pain (LBP) in patients with thoracolumbar osteoporotic vertebral compression fractures (OVCFs) following percutaneous kyphoplasty (PKP) treatment. Additionally, we aim to develop a nomogram that can accurately predict the occurrence of residual LBP. METHODS: We conducted a retrospective review of the medical records of thoracolumbar OVCFs patients who underwent PKP treatment at our hospital between July 2021 and December 2022. Residual LBP was defined as the presence of moderate or greater pain (VAS score ≥ 4) in the low back one day after surgery, and patients were divided into two groups: the LBP group and the non-LBP group. These patients were then randomly allocated to either a training or a validation set in the ratio of 7:3. To identify potential risk factors for residual LBP, we employed lasso regression for multivariate analysis, and from this, we constructed a nomogram. Subsequently, the predictive accuracy and practical clinical application of the nomogram were evaluated through a receiver operating characteristic (ROC) curve, a calibration curve, and a decision curve analysis (DCA). RESULTS: Our predictive model revealed that five variables-posterior fascial oedema, intravertebral vacuum cleft, time from fracture to surgery, sarcopenia, and interspinous ligament degeneration-were correlated with the presence of residual LBP. In the training set, the area under the ROC was 0.844 (95% CI 0.772-0.917), and in the validation set, it was 0.842 (95% CI 0.744-0.940), indicating that the model demonstrated strong discriminative performance. Furthermore, the predictions closely matched actual observations in both the training and validation sets. The decision curve analysis (DCA) curve suggested that the model provides a substantial net clinical benefit. CONCLUSIONS: We have created a novel numerical model capable of accurately predicting the potential risk factors associated with the occurrence of residual LBP following PKP in thoracolumbar OVCFs patients. This model serves as a valuable tool for guiding specific clinical decisions for patients with OVCFs.

10†µm-Level TiNb2 O7 Secondary Particles for Fast-Charging Lithium-Ion Batteries.

TiNb2 O7 with Wadsley-Roth phase delivers double theoretical specific capacity and similar working potential in comparison to spinel Li4 Ti5 O12 , the commercial high-rate anode material, and thus can enable much higher energy density of lithium-ion batteries. However, the inter-particle resistance within the high-mass-loading TiNb2 O7 electrode would impede the capacity release for practical application, especially under fast-charging conditions. Herein, 10-20 µm-size carbon-coated TiNb2 O7 secondary particle (SP-TiNb2 O7 ) consisting of initial micro-scale TiNb2 O7 particles (MP-TiNb2 O7 ) was fabricated. The high crystallinity of active material could enable fast-charge diffusion and electrochemical reaction rate within particles, and the small number of stacking layers of SP-TiNb2 O7 could reduce the large inter-particle resistance that regular particle electrode often possess and achieve high compaction density of electrodes with high mass loading. The investigation on materials structure and electrochemical reaction kinetics verified the advances of the as-fabricated SP-TiNb2 O7 in achieving superior electrochemical performance. The SP-TiNb2 O7 exhibited high reversible capacity of 292.7 mAh g-1 in the potential range of 1-3 V (Li+ /Li) at 0.1 C, delivering high-capacity release of 94.3 %, and high capacity retention of 86 % at 0.5 C for 250 cycles in half cell configuration. Particularly, the advances of such an anode were verified in practical 5 Ah-level laminated full pouch cell. The as-assembled LiFePO4 ||TiNb2 O7 full cell exhibited a high capacity of 5.08 Ah at high charging rate of 6 C (77.9 % of that at 0.2 C of 6.52 Ah), as well as an ultralow capacity decay rate of 0.0352 % for 250 cycles at 1 C, suggesting the great potential for practical fast-charging lithium-ion batteries.

Microbiome re-assembly boosts anaerobic digestion under volatile fatty acid inhibition: focusing on reactive oxygen species metabolism.

The accumulation of volatile fatty acids (VFAs) in anaerobic digestion (AD) systems resulting from food waste overload poses a risk of system collapse. However, limited understanding exists regarding the inhibitory mechanisms and effective strategies to address VFAs-induced stress. This study found that accumulated VFAs exert reactive oxygen species (ROS) stress on indigenous microbiota, particularly impacting methanogens due to their lower antioxidant capability compared to bacteria, which is supposed to be the primary reason for methanogenesis failure. To enhance the VFAs-stressed AD process, microbiome re-assembly using customized propionate-degrading consortia and bioaugmentation with concentrated digestate were implemented. Microbiome re-assembly demonstrated superior efficiency, yielding an average methane yield of 563.6±159.8 mL/L·d and reducing VFAs to undetectable levels for a minimum of 80 days. This strategy improved the abundance of Syntrophomonas, Syntrophobacter and Methanothrix, alleviating ROS stress. Conversely, microbial community in reactor with other strategy experienced an escalating intracellular damage, as indicated by the increase of ROS generation-related genes. This study fills knowledge gaps in stress-related metabolic mechanisms of anaerobic microbiomes exposed to VFAs and microbiome re-assembly to boost methanogenesis process.

Hybrid Polymer-Alloy-Fluoride Interphase Enabling Fast Ion Transport Kinetics for Low-Temperature Lithium Metal Batteries.

Low-temperature lithium metal batteries are of vital importance for cold-climate condition applications. Their realization, however, is plagued by the extremely sluggish Li+ transport kinetics in the vicinity of Li metal anode at low temperatures. Different from the widely adopted electrolyte engineering, a functional interphase design concept is proposed in this work to efficiently improve the low-temperature electrochemical reaction kinetics of Li metal anodes. As a proof of concept, we design a hybrid polymer-alloy-fluoride (PAF) interphase featuring numerous gradient fluorinated solid-solution alloy composite nanoparticles embedded in a polymerized dioxolane matrix. Systematic experimental and theoretical investigations demonstrate that the hybrid PAF interphase not only exhibits superior lithiophilicity but also provides abundant ionic conductive pathways for homogeneous and fast Li+ transport at the Li-electrolyte interface. With enhanced interfacial dynamics of Li-ion migration, the as-designed PAF-Li anode works stably for 720 h with low voltage hysteresis and dendrite-free electrode morphology in symmetric cell configurations at -40 °C. The full cells with PAF-Li anode display a commercial-grade capacity of 4.26 mAh cm-2 and high capacity retention of 74.7% after 150 cycles at -20 °C. The rational functional interphase design for accelerating ion-transfer kinetics sheds innovative insights for developing high-areal-capacity and long-lifespan lithium metal batteries at low temperatures.

Micrometer-scale single crystalline particles of niobium titanium oxide enabling an Ah-level pouch cell with superior fast-charging capability.

Wadsley-Roth phase niobium titanium oxide (TiNb2O7) is widely regarded as a promising anode candidate for fast-charging lithium-ion batteries due to its safe working potential and doubled capacity in comparison to the commercial fast-charging anode material (lithium titanium oxide, Li4Ti5O12). Although good fast charge/discharge performance was shown for nanostructured TiNb2O7, the small size would cause the low electrode compensation density and energy density of batteries, as well as parasitic reactions. Fundamental understanding of the electrochemical lithium insertion/extraction process and the structural evolution for the micrometer-scale single crystalline TiNb2O7 (MSC-TiNb2O7) could provide insights to understand its inherent properties and possibility for fast-charging application. Here, we revealed the highly reversible structural evolution of the MSC-TiNb2O7 during the lithiation/delithiation processes. Interestingly, an ion-conductive lithium niobate interphase was in situ formed on the MSC-TiNb2O7 surface during the formation cycle, which could facilitate fast ion diffusion on the material surface and support fast electrochemical reaction kinetics. Experimentally, the MSC-TiNb2O7 delivered a high reversible capacity of 291.9 mA h g-1 at 0.5C with a high initial Coulombic efficiency (>95%), and showed superb rate capability with a reasonable capacity of 55.6 mA h g-1 under a high current density of 40C. An Ah-level pouch cell with a lithium cobalt oxide (LiCoO2) cathode exhibited 91.5% capacity retention at 3C charging rate, which revealed the significant role of high crystallinity and in situ formation of an ion conductive nano-interphase in realizing fast charging capability of practical TiNb2O7-based lithium-ion batteries.

Co-production of lactate and volatile fatty acids through repeated-batch fermentation of fruit and vegetable waste: Effect of cycle time and replacement ratio.

In this study, repeated-batch fermentation was used to convert fruit and vegetable waste to lactate and volatile fatty acids (VFAs), which are essential carbon sources for medium-chain fatty acids (MCFAs) production. The effect of cycle time and replacement ratio on acidification in long-term fermentation was investigated. The results showed that they had a significant impact on product yield, productivity, and type of products. Considering the yield, productivity, and lactate/VFAs ratio, a replacement ratio of 30% and a cycle time of 2 d may be more suitable for further production of MCFAs. Its productivity and lactate/VFAs ratio were 4.07 ± 0.24 g/(L·d) and 5 ± 0.6, respectively. The lactic acid bacteria, such as Enterococcus (63%) and Lactobacillus (33%), stabilized in the reactor, resulting in the generation of both lactate and VFAs by heterolactic fermentation. The present study demonstrated a new strategy with the potential to recover high-value products from organic waste streams.

Reaction-passivation mechanism driven materials separation for recycling of spent lithium-ion batteries.

Development of effective recycling strategies for cathode materials in spent lithium-ion batteries are highly desirable but remain significant challenges, among which facile separation of Al foil and active material layer of cathode makes up the first important step. Here, we propose a reaction-passivation driven mechanism for facile separation of Al foil and active material layer. Experimentally, >99.9% separation efficiency for Al foil and LiNi0.55Co0.15Mn0.3O2 layer is realized for a 102 Ah spent cell within 5 mins, and ultrathin, dense aluminum-phytic acid complex layer is in-situ formed on Al foil immediately after its contact with phytic acid, which suppresses continuous Al corrosion. Besides, the dissolution of transitional metal from LiNi0.55Co0.15Mn0.3O2 is negligible and good structural integrity of LiNi0.55Co0.15Mn0.3O2 is well-maintained during the processing. This work demonstrates a feasible approach for Al foil-active material layer separation of cathode and can promote the green and energy-saving battery recycling towards practical applications.

Tight Binding and Dual Encapsulation Enabled Stable Thick Silicon/Carbon Anode with Ultrahigh Volumetric Capacity for Lithium Storage.

Silicon (Si) is regarded as one of the most promising anode materials for high-performance lithium-ion batteries (LIBs). However, how to mitigate its poor intrinsic conductivity and the lithiation/delithiation-induced large volume change and thus structural degradation of Si electrodes without compromising their energy density is critical for the practical application of Si in LIBs. Herein, an integration strategy is proposed for preparing a compact micron-sized Si@G/CNF@NC composite with a tight binding and dual-encapsulated architecture that can endow it with superior electrical conductivity and deformation resistance, contributing to excellent cycling stability and good rate performance in thick electrode. At an ultrahigh mass loading of 10.8 mg cm-2 , the Si@G/CNF@NC electrode also presents a large initial areal capacity of 16.7 mA h cm-2 (volumetric capacity of 2197.7 mA h cm-3 ). When paired with LiNi0.95 Co0.02 Mn0.03 O2 , the pouch-type full battery displays a highly competitive gravimetric (volumetric) energy density of ≈459.1 Wh kg-1 (≈1235.4 Wh L-1 ).

Probing Hybrid LiFePO4/FePO4 Phases in a Single Olive LiFePO4 Particle and Their Recovering from Degraded Electric Vehicle Batteries.

The recycling of LiFePO4 from degraded lithium-ion batteries (LIBs) from electric vehicles (EVs) has gained significant attention due to resource, environment, and cost considerations. Through neutron diffraction, X-ray photoelectron spectroscopy, and transmission electron microscopy, we revealed continuous lithium loss during battery cycling, resulting in a Li-deficient state (Li1-xFePO4) and phase separation within individual particles, where olive-shaped FePO4 nanodomains (5-10 nm) were embedded in the LiFePO4 matrix. The preservation of the olive-shaped skeleton during Li loss and phase change enabled materials recovery. By chemical compensation for the lithium loss, we successfully restored the hybrid LiFePO4/FePO4 structure to pure LiFePO4, eliminating nanograin boundaries. The regenerated LiFePO4 (R-LiFePO4) exhibited a high crystallinity similar to the fresh counterpart. This study highlights the importance of topotactic chemical reactions in structural repair and offers insights into the potential of targeted Li compensation for energy-efficient recycling of battery electrode materials with polyanion-type skeletons.

Tandem addition of nucleophilic and electrophilic reagents to vinyl phosphinates: the stereoselective formation of organophosphorus compounds with congested tertiary carbons.

Carbon anions formed via the addition of Grignard reagents to SP-vinyl phosphinates were modified with electrophilic reagents to afford organophosphorus compounds with diverse carbon skeletons. The electrophiles included acids, aldehydes, epoxy groups, chalcogens and alkyl halides. When alkyl halides were used, bis-alkylated products were afforded. Substitution reactions or polymerization occurred when the reaction was applied to vinyl phosphine oxides.

Mitigating Concentration Polarization through Acid-Base Interaction Effects for Long-Cycling Lithium Metal Anodes.

Lithium (Li) metal has attracted great attention as a promising high-capacity anode material for next-generation high-energy-density rechargeable batteries. Nonuniform Li+ transport and uneven Li plating/stripping behavior are two key factors that deteriorate the electrochemical performance. In this work, we propose an interphase acid-base interaction effect that could regulate Li plating/stripping behavior and stabilize the Li metal anode. ZSM-5, a class of zeolites with ordered nanochannels and abundant acid sites, was employed as a functional interface layer to facilitate Li+ transport and mitigate the cell concentration polarization. As a demonstration, a pouch cell with a high-areal-capacity LiNi0.95Co0.02Mn0.03O2 cathode (3.7 mAh cm-2) and a ZSM-5 modified thin lithium anode (50 µm) delivered impressive electrochemical performance, showing 92% capacity retention in 100 cycles (375.7 mAh). This work reveals the effect of acid-base interaction on regulating lithium plating/stripping behaviors, which could be extended to developing other high-performance alkali metal anodes.

Percutaneous Kyphoplasty to Relieve the Rib Region Pain in Osteoporotic Thoracic Vertebral Fracture Patients Without Local Pain of Fractured Vertebra.

BACKGROUND: Osteoporotic vertebral compression fractures (OVCF) are common. A few patients with thoracic vertebral fracture show pain in the bilateral rib region but not at the fracture site. The point of specific tenderness in the rib region cannot be located. It is not clear whether percutaneous kyphoplasty (PKP) can relieve the pain in the bilateral rib region in these patients. OBJECTIVE: To check whether PKP can alleviate the rib region pain in thoracic vertebral fracture patients without local pain at the fractured vertebra. STUDY DESIGN: Retrospective study. SETTING: The study was carried out at a university hospital. METHODS: We performed a retrospective analysis of thoracic vertebral fracture patients admitted to our hospital for PKP surgery between January 2018 and June 2022. The main clinical manifestations of these patients were pain in the bilateral rib region but no local tenderness and percussion pain at the fractured vertebra. CT and MRI examinations of the thoracic vertebrae were performed after admission. PKP was performed under general anesthesia after no surgical contraindication. Visual analog scale (VAS) scores and heights of the anterior, middle, and posterior edges of the fractured vertebra before the surgery, one day after surgery, and one month after surgery were compared. Also, the Cobb angles formed by the upper and lower endplate of the fractured vertebra before the surgery, one day after surgery, and one month after surgery were compared. RESULTS: A total of 50 patients were included in this study (3 men and 47 women, with an average age of 72.46 ± 8.15 years), of which 7 patients had 2 segmental fractures, so a total of 57 vertebrae were included. The VAS scores on day one and one month after the surgery were significantly lower than that before the surgery. The heights of the anterior, middle, and posterior edges of the fractured vertebra on day one after the surgery were significantly higher than those before the surgery. The Cobb angle of the fractured vertebra on day one after the surgery was lower than that before the surgery. The vertebrae of 23 patients were examined using x-ray one month after the surgery. The heights of the anterior, middle, and posterior edges of the fractured vertebra one month after the surgery were also significantly higher than those before the surgery but significantly lower than those one day after the surgery. Also, the Cobb angle of the fractured vertebra one month after the surgery was significantly lower than that before the surgery. LIMITATIONS: This was a retrospective study, which may be prone to selection and recall bias. Single-center non-controlled studies may also introduce bias. CONCLUSION: The exact location of the pain in the rib region caused by thoracic fracture cannot be identified usually. PKP can alleviate the rib region pain caused by the thoracic fracture.

Locking Active Li Metal through Localized Redistribution of Fluoride Enabling Stable Li-Metal Batteries.

The creation of fluorinated interphase has emerged as an effective strategy for improving Li-metal anodes for rechargeable high-energy batteries. In contrast to the introduction of fluorine-containing species through widely adopted electrolyte engineering, a Li-metal composite design is reported in which LiF can locally redistribute on the Li-metal surface in liquid electrolytes via a dissolution-reprecipitation mechanism, and enable the formation of a high-fluorine-content solid electrolyte interphase (SEI). For validation, a Li/Li22 Sn5 /LiF ternary composite is investigated, where the as-formed LiF-rich SEI locks the active Li metal from corrosive electrolyte. The Li/Li22 Sn5 /LiF anode displays an impressive average Coulombic efficiency (ACE, ≈99.2%) at 1 mA cm-2 and 1 mAh cm-2 in a carbonate electrolyte and a remarkable cycling life of over 1600 h at 1 mA cm-2 and 2 mAh cm-2 . Applied to a LiCoO2 full cell with a high cathode areal capacity of 4.0 mAh cm-2 , a high capacity retention of ≈91.1% is realized for 100 cycles at 0.5 C between 2.8 to 4.5 V with a low negative/positive (N/P) ratio of 2:1. This design is conceptually different from the design employing the widely used fluorine-containing electrolyte additive and provides an alternative approach to realize reliable Li-metal batteries.

Enabling the complete valorization of hybrid Pennisetum: Directly using alkaline black liquor for preparing UV-shielding biodegradable films.

The conversion of lignocellulosic biomass into various high-value chemicals has been a rapid expanding research topic in industry and agriculture. Among them, alkaline removal and utilization of lignin are important for the accelerated degradation of biomass. Modern biorefinery has been focusing the vision on the advancement of economical, green, and environmentally friendly processes. Therefore, it is indispensable to develop cost-effective and simple biomass conversion technologies to obtain high-value products. In this study, the black liquor (BL) obtained from the alkaline pretreatment of biomass was added to polyvinyl alcohol (PVA) solution and used to prepare degradable ultraviolet (UV) shielding films, achieving direct and efficient utilization of the aqueous phase from alkaline pretreatment. This method avoids the extraction step of lignin fraction from black liquor, which can be directly utilized as the raw materials of films preparation. In addition, the direct use of alkaline BL results in films with similar UV-shielding properties, higher physical strength, and similar thermal stability compared with films made by commercial alkaline lignin. Therefore, this strategy is proposed for alkaline-pretreated biorefineries as a simple way to convert waste BL into valuable products and partially recover unconsumed sodium hydroxide to achieve as much integration of biomass and near zero-waste biorefineries as possible.

Stable interphase chemistry of textured Zn anode for rechargeable aqueous batteries.

Despite the advances of aqueous zinc (Zn) batteries as sustainable energy storage systems, their practical application remains challenging due to the issues of spontaneous corrosion and dendritic deposits at the Zn metal anode. In this work, conformal growth of zinc hydroxide sulfate (ZHS) with dominating (001) facet was realized on (002) plane-dominated Zn metal foil fabricated through a facile thermal annealing process. The ZHS possessed high Zn2+ conductivity (16.9 mS cm-1) and low electronic conductivity (1.28 × 104 Ω cm), and acted as a heterogeneous and robust solid electrolyte interface (SEI) layer on metallic Zn electrode, which regulated the electrochemical Zn plating behavior and suppressed side reactions simultaneously. Moreover, low self-diffusion barrier along the (002) plane promoted the 2D diffusion and horizontal electrochemical plating of metallic Zn for (002)-textured Zn electrode. Consequently, the as-achieved Zn electrode exhibited remarkable cycling stability over 7000 cycles at 2 mA cm-2 and 0.5 mAh cm-2 with a low overpotential of 25 mV in symmetric cells. Pairing with a MnO2 cathode, the as-achieved Zn electrode achieved stable cell cycling with 92.7% capacity retention after 1000 cycles at 10 C with a remarkable average Coulombic efficiency of 99.9%.

CircFOXK2 Promotes the Progression of Osteoarthritis by Regulating the miR-4640-5p/NOTCH2 Axis.

OBJECTIVE: Osteoarthritis (OA) is the most common age-related chronic and disabling joint disease, frequently causing pain and disability in the adult population. Given that there are no proven disease-modifying drugs for OA, it is urgent to gain a deeper understanding of OA pathogenesis. This study intended to uncover the circFOXK2 regulation in OA. METHODS: Firstly, in vitro OA cell model was constructed by treating murine chondrocytes with interleukin (IL)-1ß. Then, a series of functional assays were conducted to evaluate the effect of circFOXK2 on OA progression in murine chondrocytes. Bioinformatics analysis and mechanism investigations were performed to investigate the competitive endogenous RNA (ceRNA) network of circFOXK2 in OA. RESULTS: CircFOXK2 is overexpressed in IL-1ß-treated chondrocyte. We confirmed the cyclic structure and cytoplasmic distribution of circFOXK2. Functionally, circFOXK2 promotes chondrocyte apoptosis and extracellular matrix (ECM) degradation but inhibiting chondrocyte proliferation. Mechanically, circFOXK2 competitively binds to microRNA-4640-5p (miR-4640-5p) to enhance NOTCH2 expression in OA, affecting OA progression. Besides, circFOXK2 could motivate the Notch pathway to accelerate OA progression. CONCLUSION: CircFOXK2/miR-4640-5p/NOTCH2 axis stimulates the Notch pathway to promote the transcription of inflammatory cytokines (IL33, IL17F and IL6), consequently facilitating OA progression in murine chondrocytes.

Functionally Gradient Silicon/Graphite Composite Electrodes Enabling Stable Cycling and High Capacity for Lithium-Ion Batteries.

Silicon (Si) is regarded as one of the most promising anode materials for high-energy-density lithium (Li)-ion batteries (LIBs). However, Li insertion/extraction induced large volume change, which can lead to the fracture of the Si material itself and the delamination/pulverization of electrodes, is the major challenge for the practical application of Si-based anodes. Herein, a facile and scalable multilayer coating approach was proposed for the large-scale fabrication of functionally gradient Si/graphite (Si/Gr) composite electrodes to simultaneously mitigate the volume change-caused structural degradation and realize high capacity by regulating the spatial distributions of Si and Gr particles in the electrodes. Both our experimental characterizations and chemomechanical simulations indicated that, with a parabolic gradient (PG) distribution of Si through the thickness direction that the two Si-poor surface layers guarantee the major mechanical support and the middle Si-rich layer ensures the high capacity, the as-prepared PG-Si/Gr electrode can not only effectively improve the stability of the electrode structure but also efficiently enable high capacity and stable electrochemical reactions. Consequently, the PG-Si/Gr electrode with a mass loading of 3.15 mg cm-2 exhibited a reversible capacity of 579.2 mAh g-1 (1.82 mAh cm-2) after 200 cycles at 0.2C. Even with a mass loading of 8.45 mg cm-2, the PG-Si/Gr anodes still delivered a high reversible capacity of 4.04 mAh cm-2 after 100 cycles and maintained excellent cycling stability. Moreover, when paired with a commercial LiNi0.5Mn0.3Co0.2O2 (NCM532) cathode (9.56 mg cm-2), the PG-Si/Gr||NCM532 full cell revealed an initial reversible areal capacity of 1.64 mAh cm-2 and sustained a stable areal capacity of 0.94 mAh cm-2 at 0.2C after 100 cycles.

LiNi0.5Mn1.5O4 Cathode Microstructure for All-Solid-State Batteries.

Solid-state batteries (SSBs) have received attention as a next-generation energy storage technology due to their potential to superior deliver energy density and safety compared to commercial Li-ion batteries. One of the main challenges limiting their practical implementation is the rapid capacity decay caused by the loss of contact between the cathode active material and the solid electrolyte upon cycling. Here, we use the promising high-voltage, low-cost LiNi0.5Mn1.5O4 (LNMO) as a model system to demonstrate the importance of the cathode microstructure in SSBs. We design Al2O3-coated LNMO particles with a hollow microstructure aimed at suppressing electrolyte decomposition, minimizing volume change during cycling, and shortening the Li diffusion pathway to achieve maximum cathode utilization. When cycled with a Li6PS5Cl solid electrolyte, we demonstrate a capacity retention above 70% after 100 cycles, with an active material loading of 27 mg cm-2 (2.2 mAh cm-2) at a current density of 0.8 mA cm-2.