Weak-Interaction Environment in a Composite Electrolyte Enabling Ultralong-Cycling High-Voltage Solid-State Lithium Batteries.

Poly(vinylidene fluoride) (PVDF)-based solid electrolytes with a Li salt-polymer-little residual solvent configuration are promising candidates for solid-state batteries. Herein, we clarify the microstructure of PVDF-based composite electrolyte at the atomic level and demonstrate that the Li+-interaction environment determines both interfacial stability and ion-transport capability. The polymer works as a "solid diluent" and the filler realizes a uniform solvent distribution. We propose a universal strategy of constructing a weak-interaction environment by replacing the conventional N,N-dimethylformamide (DMF) solvent with the designed 2,2,2-trifluoroacetamide (TFA). The lower Li+ binding energy of TFA forms abundant aggregates to generate inorganic-rich interphases for interfacial compatibility. The weaker interactions of TFA with PVDF and filler achieve high ionic conductivity (7.0 × 10-4 S cm-1) of the electrolyte. The solid-state Li||LiNi0.8Co0.1Mn0.1O2 cells stably cycle 4900 and 3000 times with cutoff voltages of 4.3 and 4.5 V, respectively, as well as deliver superior stability at -20 to 45 °C and a high energy density of 300 Wh kg-1 in pouch cells.

Inhibiting Formation and Reduction of Li2 CO3 to LiCx at Grain Boundaries in Garnet Electrolytes to Prevent Li Penetration.

Poor ion and high electron transport at the grain boundaries (GBs) of ceramic electrolytes are the primary reasons for lithium filament infiltration and short-circuiting of all-solid-state lithium metal batteries (ASLMBs). Herein, it is discovered that Li2 CO3 at the GBs of Li7 La3 Zr2 O12 (LLZO) sheets is reduced to highly electron-conductive LiCx during cycling, resulting in lithium penetration of LLZO. The ionic and electronic conductivity of the GBs within LLZO can be simultaneously tuned using sintered Li3 AlF6 . The generated LiAlO2 (LAO) infusion and F-doping at the GBs of LLZO (LAO-LLZOF) significantly reduce the Li2 CO3 content and broaden the energy bandgap of LLZO, which decreases the electronic conductivity of LAO-LLZOF. LAO forms a 3D continuous ion transport network at the GB that significantly improves the total ionic conductivity. Lithium penetration within LLZO is suppressed and an all-solid-state LiFePO4 /LAO-LLZOF/Li battery stably cycled for 5500 cycles at 3 C. This work reveals the chemistry of Li2 CO3 at the LLZO GBs during cycling, presents a novel lithium penetration mechanism within garnet electrolytes, and provides an innovative method to simultaneously regulate the ion and electron transport at the GBs in garnet electrodes for advanced ASLMBs.

Lithium-ion spontaneous exchange and synergistic transport in ceramic-liquid hybrid electrolytes for highly efficient lithium-ion transfer.

Ceramic electrolytes are important in ceramic-liquid hybrid electrolytes (CLHEs), which can effectively solve the interfacial issues between the electrolyte and electrodes in solid-state batteries and provide a highly efficient Li-ion transfer for solid-liquid Li metal batteries. Understanding the ionic transport mechanisms in CLHEs and the corresponding role of ceramic electrolytes is crucial for a rational design strategy. Herein, the Li-ion transfer in the ceramic electrolytes of CLHEs was confirmed by tracking the 6Li and 7Li substitution behavior through solid-state nuclear magnetic resonance spectroscopy. The ceramic and liquid electrolytes simultaneously participate in Li-ion transport to achieve highly efficient Li-ion transfer in CLHEs. A spontaneous Li-ion exchange was also observed between ceramic and liquid electrolytes, which serves as a bridge that connects the ceramic and liquid electrolytes, thereby greatly strengthening the continuity of Li-ion pathways in CLHEs and improving the kinetics of Li-ion transfer. The importance of an abundant solid-liquid interface for CLHEs was further verified by the enhanced electrochemical performance in LiFePO4/Li and LiNi0.8Co0.1Mn0.1O2/Li batteries from the generated interface. This work provides a clear understanding of the Li-ion transport pathway in CLHEs that serves as a basis to build a universal Li-ion transport model of CLHEs.

Positive association of serum FUT8 activity with renal tubulointerstitial injury in IgA nephropathy patients.

BACKGROUND: α-1,6 Fucosyltransferase (FUT8) appears to play an essential role in the pathogenesis of renal fibrosis. However, it remained unknown whether FUT8 also contributed to renal fibrosis in immunoglobulin A nephropathy (IgAN). In the present study, we explored the association of serum FUT8 activity with renal tubulointerstitial injury in IgAN patients. METHODS: Serum FUT8 activity was measured in 135 IgAN patients and 68 healthy controls from January 2016 to December 2018. The relationships of serum FUT8 activity with clinical and pathological features were analyzed. RESULTS: Relative to healthy controls, IgAN patients had significantly higher serum FUT8 activity and upregulation of renal FUT8 protein (p < .05). Among IgAN patients, there was a positive correlation of serum FUT8 activity with renal FUT8 protein expression (p < .05). Multivariable logistic regression analyses showed that serum FUT8 activity was significantly associated with serum creatinine and eGFR (p < .05). Based on a cut-off value determined from ROC curve analysis, we divided IgAN patients into a low serum FUT8 activity group (≤12.2 pmol/h/mL, n = 40) and a high serum FUT8 activity group (>12.2 pmol/h/ml, n = 95). The high serum FUT8 activity group had a higher Oxford T score, increased inflammatory cell infiltration, more severe fibrosis and poor renal function (p < .05). CONCLUSION: Serum FUT8 activity was positive association with renal tubulointerstitial injury in IgAN patients.

Stable Interface Chemistry and Multiple Ion Transport of Composite Electrolyte Contribute to Ultra-long Cycling Solid-State LiNi0.8 Co0.1 Mn0.1 O2 /Lithium Metal Batteries.

Severe interfacial side reactions of polymer electrolyte with LiNi0.8 Co0.1 Mn0.1 O2 (NCM811) cathode and Li metal anode restrict the cycling performance of solid-state NCM811/Li batteries. Herein, we propose a chemically stable ceramic-polymer-anchored solvent composite electrolyte with high ionic conductivity of 6.0×10-4  S cm-1 , which enables the solid-state NCM811/Li batteries to cycle 1500 times. The Li1.4 Al0.4 Ti1.6 (PO4 )3 nanowires (LNs) can tightly anchor the essential N, N-dimethylformamide (DMF) in poly(vinylidene fluoride) (PVDF), greatly enhancing its electrochemical stability and suppressing the side reactions. We identify the ceramic-polymer-liquid multiple ion transport mechanism of the LNs-PVDF-DMF composite electrolyte by tracking the 6 Li and 7 Li substitution behavior via solid-state NMR. The stable interface chemistry and efficient ion transport of LNs-PVDF-DMF contribute to superior performances of the solid-state batteries at wide temperature range of -20-60 °C.