Anion-modulated Ion Conductor with Chain Conformational Transformation for stabilizing Interfacial Phase of High-Voltage Lithium Metal Batteries.

In solid-state lithium metal batteries (SSLMBs), the inhomogeneous electrolyte-electrode interphase layer aggravates the interfacial stability, leading to discontinuous interfacial ion/charge transport and continuous degradation of the electrolyte. Herein, we constructed an anion-modulated ionic conductor (AMIC) that enables in situ construction of electrolyte/electrode interphases for high-voltage SSLMBs by exploiting conformational transitions under multiple interactions between polymer and lithium salt anions. Anions modulate the decomposition behavior of supramolecular poly (vinylene carbonate) (PVC) at the electrode interface by changing the spatial conformation of the polymer chains, which further enhances ion transport and stabilizes the interfacial morphology. In addition, the AMIC weakens the "Li+-solvation" and increases Li+ vehicle sites, thereby enhancing the lithium-ion transport number (tLi +=~0.67). Consequently, Li || LiNi0.8Co0.1Mn0.1O2 cell maintains about 85 % capacity retention and Coulombic efficiency >99.8 % in 200 cycles at a charge cut-off voltage of 4.5 V. This study provides a new understanding of lithium salt anions regulating polymer chain segment behavior in the solid-state polymer electrolyte (SPE) and highlights the importance of the ion environment in the construction of interfacial phases and ionic conduction.

IL-37 Represses the Autoimmunity in Myasthenia Gravis via Directly Targeting Follicular Th and B Cells.

IL-37 is a newly identified immune-suppressive factor; however, the function, cellular sources, and mechanism of IL-37 in humoral immunity and Myasthenia gravis (MG) are still unclear. In this study, we found IL-37 were substantially downregulated in the serum and PBMCs of MG patients compared with healthy controls. The lower IL-37 was associated with severer disease (quantitative MG score) and higher follicular Th (Tfh)/Tfh17 and B cell numbers. Flow cytometry analysis revealed that IL-37 was mainly produced by CD4+ T cells without overlapping with Th1, Th17, and Tfh subsets in MG patients. Regulatory IL-37+ T cell rarely expressed Foxp3 and CD25 but produced numerous IL-4. Tfh and B cell expressed high levels of SIGIRR, the receptor of IL-37, in MG patients. Mechanically, IL-37 directly bond to SIGIRR, repressed the proliferation, cytokine production of Tfh and B cells, and the secretion of autoantibody via inhibition of STAT3 signaling in Tfh and B cells.

Double-negative T cells remarkably promote neuroinflammation after ischemic stroke.

CD3+CD4-CD8- T cells (double-negative T cells; DNTs) have diverse functions in peripheral immune-related diseases by regulating immunological and inflammatory homeostasis. However, the functions of DNTs in the central nervous system remain unknown. Here, we found that the levels of DNTs were dramatically increased in both the brain and peripheral blood of stroke patients and in a mouse model in a time-dependent manner. The infiltrating DNTs enhanced cerebral immune and inflammatory responses and exacerbated ischemic brain injury by modulating the FasL/PTPN2/TNF-α signaling pathway. Blockade of this pathway limited DNT-mediated neuroinflammation and improved the outcomes of stroke. Our results identified a critical function of DNTs in the ischemic brain, suggesting that this unique population serves as an attractive target for the treatment of ischemic stroke.

Self-Propagating Enabling High Lithium Metal Utilization Ratio Composite Anodes for Lithium Metal Batteries.

Constructing three-dimensional (3D) structural composite lithium metal anode by molten-infusion strategy is an effective strategy to address the severe problems of Li dendritic growth and huge volume changes. However, various challenges, including uncontrollable Li loading, dense inner structure, and low Li utilization, still need to be addressed for the practical application of 3D Li anode. Herein, we propose a self-propagating method, which is realized by a synergistic effect of chemical reaction and capillarity effect on porous scaffold surface, for fabricating a flexible 3D composite Li metal anode with high Li utilization ratio and controllable low Li loading. The composite 3D anode possesses controllable low loading (8.0-24.0 mAh cm-2) and uniform grid structure, realizing a stable cycling over 600 h at a high Li metal utilization ratio over 75%. The proposed strategy for fabricating composite 3D anode could promote the practical application of Li metal batteries.

Prelithiated V2 C MXene: A High-Performance Electrode for Hybrid Magnesium/Lithium-Ion Batteries by Ion Cointercalation.

The pursuit of high reversible capacity and long cycle life for rechargeable batteries has gained extensive attention in recent years, and the development of applicable electrode materials is the key point. Herein, thanks to the preintercalation of lithium ions, a stable and highly conductive nanostructure of V2 C MXene is successfully fabricated via a facile self-discharge mechanism, which provides open spaces for rapid ion diffusion and guarantees fast electron transport. Taking the prelithiated V2 C as electrode, an outstanding initial coulombic efficiency of 80% and an impressive capacity retention of ≈98% after 5000 charge/discharge cycles are achieved for lithium-ion batteries. Especially, it demonstrates a fascinating reversible capacity of up to 230.3 mA h g-1 at 0.02 A g-1 and a long cycling life of 82% capacity retention over 480 cycles in the hybrid magnesium/lithium-ion batteries. In addition, the Mg2+ and Li+ ions cointercalation mechanism of the prelithiated V2 C is elucidated through ex situ X-ray diffraction and X-ray photoelectron spectroscopy characterizations. This work not only offers an effective approach to compensate the large initial lithium loss of high-capacity anode materials but also opens up a new and viable avenue to develop promising hybrid Mg/Li-storage materials with eminent electrochemical performance.

Chemical Energy Release Driven Lithiophilic Layer on 1 m2 Commercial Brass Mesh toward Highly Stable Lithium Metal Batteries.

It is imperative to explore practical methods and materials to drive the development of high energy density lithium metal batteries. The constuciton of nanostructure electrodes and surface engineering on the current collectors are the two most effective strategies to regulate the homogeneous Li plating/stripping to relieve the Li dendrites and infinite volume change problems. Based on the low stacking fault energy of the Cu-Zn alloy, we present a novel chemical energy release induced surface atom diffusion strategy, which is achieved by the negative Gibbs free energy from the surface oxidation reaction and subsequent replacement reaction under thermal treatment in air, to realize a uniform upper ZnO nanoparticles coating. Furthermore, we apply the modified brass mesh as a lithiophilic current collector to decrease the Li deposition nucleation overpotential and effectively restrain the Li dendrite growth. The modified brass current collector achieves a long-term cycling stability of 500 cycles at 2.0 mA cm-2. We have verified the effectiveness of our chemical energy release modification strategy on a 1 m2 brass mesh and other Cu alloy (Tin bronze mesh), which demonstrates its great opportunities for scalable and safe lithium metal batteries.

Early Lithium Plating Behavior in Confined Nanospace of 3D Lithiophilic Carbon Matrix for Stable Solid-State Lithium Metal Batteries.

Considerable efforts are devoted to relieve the critical lithium dendritic and volume change problems in the lithium metal anode. Constructing uniform Li+ distribution and lithium "host" are shown to be the most promising strategies to drive practical lithium metal anode development. Herein, a uniform Li nucleation/growth behavior in a confined nanospace is verified by constructing vertical graphene on a 3D commercial copper mesh. The difference of solid-electrolyte interphase (SEI) composition and lithium growth behavior in the confined nanospace is further demonstrated by in-depth X-ray photoelectron spectrometer (XPS) and line-scan energy dispersive X-ray spectroscopic (EDS) methods. As a result, a high Columbic efficiency of 97% beyond 250 cycles at a current density of 2 mA cm-2 and a prolonged lifespan of symmetrical cell (500 cycles at 5 mA cm-2 ) can be easily achieved. More meaningfully, the solid-state lithium metal cell paired with the composite lithium anode and LiNi0.5 Co0.2 Mn0.3 O2 (NCM) as the cathode also demonstrate reduced polarization and extended cycle. The present confined nanospace-derived hybrid anode can further promote the development of future all solid-state lithium metal batteries.

Single-Crystal α-Fe2O3 with Engineered Exposed (001) Facet for High-Rate, Long-Cycle-Life Lithium-Ion Battery Anode.

Designing electrode materials with engineered exposed facets provides a novel strategy to improve their electrochemical properties. However, the controllability of the exposed facet remains a daunting challenge, and a deep understanding of the correlation between exposed facet and Li+-transfer behavior has been rarely reported. In this work, single-crystal α-Fe2O3 hexagonal nanosheets with an exposed (001) facet are prepared with the assistance of aluminum ions through a one-step hydrothermal process, and structural characterizations reveal an Al3+-concentration-dependent-growth mechanism for the α-Fe2O3 nanosheets. Furthermore, such α-Fe2O3 nanosheets, when used as lithium-ion battery anodes, exhibit high specific capacity (1261.3 mAh g-1 at 200 mA g-1), high rate capability (with a reversible capacity of approximately 605 mAh g-1 at 10 A g-1), and excellent cyclic stability (with a capacity of over 900 mAh g-1 during 500 cycles). The superior electrochemical performance of α-Fe2O3 nanosheets is attributed to the pseudocapacitive behavior, Al-doping in the α-Fe2O3 structure, and improved Li+-transfer property across the (001) facet, as elucidated by first-principles calculations based on density functional theory. These results reveal the underlying mechanism of Li+ transfer across different facets and thus provide insights into the understanding of the excellent electrochemical performance.

Hydrothermal synthesis of graphene/nickel oxide nanocomposites used as the electrode for supercapacitors.

Graphene (GR)-based nanocomposites with different mass ratios of NiO and GR are prepared via hydrothermal method using Ni(NO3)2 as the origin of nickel and urea as the hydrolysis-controlling agent. The morphology and electrochemical performance of the GR/NiO nanocomposites are closely associated with the mass ratios of GR to NiO. The chemical composition and morphology of the composites together with the pure GR and NiO are characterized by thermogravimetric analysis (TGA), X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). It is found that the GR sheets and NiO particles form uniform nanocomposites with the NiO particles absorbed on the GR surface. A specific capacitance of 384 F g(-1) at a current density of 0.1 A g(-1) is achieved when the coating amount of NiO is up to 74 wt%. In addition, the attenuation of the specific capacitance is less than 6% after 500 cycles, indicating such nanocomposite has excellent cycling performance.

Stabilizing a Li1.3Al0.3Ti1.7(PO4)3/Li metal anode interface in solid-state batteries with a LiF/Cu-rich multifunctional interlayer.

Li1.3Al0.3Ti1.7(PO4)3 (LATP) has attracted much attention due to its high ionic conductivity, good air stability and low cost. However, the practical application of LATP in all-solid-state lithium batteries faces serious challenges, such as high incompatibility with lithium metal and high interfacial impedance. Herein, a CuF2 composite layer was constructed at a Li/LATP interface by a simple drop coating method. CuF2 in the interlayer reacts with lithium metal in situ to form a multifunctional interface rich in Cu and LiF. The multifunctional layer not only brings about close interfacial contact between LATP and Li metal, but also effectively prevents the electrochemical reaction of LATP with Li metal, and suppresses the electron tunneling and dendrite growth at the interface. The interfacial resistance of Li/CuF2@LATP/Li symmetric batteries is significantly reduced from 562 to 92 Ω, and the critical current density is increased to 1.7 mA cm-2. An impressive stable cycle performance of over 6000 h at 0.1 mA cm-2/0.1 mA h cm-2, 2200 h at 0.2 mA cm-2/0.2 mA h cm-2 and 1600 h at 0.3 mA cm-2/0.3 mA h cm-2 is achieved. Full batteries of LiFePO4/CuF2@LATP/Li also show a high capacity retention ratio of 80.3% after 540 cycles at 25 °C. This work provides an effective and simple composite layer solution to address the interfacial problem of Li/LATP.