Nanoscale Visualization of Lithium Plating/Stripping Tuned by On-site Formed Solid Electrolyte Interphase in All-Solid-State Lithium-Metal Batteries.

The interfacial processes, mainly the lithium (Li) plating/stripping and the evolution of the solid electrolyte interphase (SEI), are directly related to the performance of all-solid-state Li-metal batteries (ASSLBs). However, the complex processes at solid-solid interfaces are embedded under the solid-state electrolyte, making it challenging to analyze the dynamic processes in real time. Here, using in situ electrochemical atomic force microscopy and optical microscopy, we directly visualized the Li plating/stripping/replating behavior, and measured the morphological and mechanical properties of the on-site formed SEI at nanoscale. Li spheres plating/stripping/replating at the argyrodite solid electrolyte (Li6 PS5 Cl)/Li electrode interface is coupled with the formation/wrinkling/inflating of the SEI on its surface. Combined with in situ X-ray photoelectron spectroscopy, details of the stepwise formation and physicochemical properties of SEI on the Li spheres are obtained. It is shown that higher operation rates can decrease the uniformity of the Li+ -conducting networks in the SEI and worsen Li plating/stripping reversibility. By regulating the applied current rates, uniform nucleation and reversible plating/stripping processes can be achieved, leading to the extension of the cycling life. The in situ analysis of the on-site formed SEI at solid-solid interfaces provides the correlation between the interfacial evolution and the electrochemical performance in ASSLBs.

Interfacial Evolution of the Solid Electrolyte Interphase and Lithium Deposition in Graphdiyne-Based Lithium-Ion Batteries.

All-carbon graphdiyne (GDY)-based materials have attracted extensive attention owing to their extraordinary structures and outstanding performance in electrochemical energy storage. Straightforward insights into the interfacial evolution at GDY electrode/electrolyte interface could crucially enrich the fundamental comprehensions and inspire targeted regulations. Herein, in situ optical microscopy and atomic force microscopy monitoring of the GDY and N-doped GDY electrodes reveal the interplay between the solid electrolyte interphase (SEI) and Li deposition. The growth and continuous accumulation of the flocculent-like SEI is directly tracked at the surface of GDY electrode. Moreover, the nanoparticle-shaped SEI homogeneously propagates at the interface when N configurations are involved, providing a critical clue for the N-doping effects of stabilizing interfaces and homogenizing Li deposition. This work probes into the dynamic evolution and structure-reactivity correlation in detail, creating effective strategies for GDY-based materials optimization in lithium-ion batteries.

Surface Degradation of Single-crystalline Ni-rich Cathode and Regulation Mechanism by Atomic Layer Deposition in Solid-State Lithium Batteries.

Single-crystalline Ni-rich cathode (SC-NCM) has attracted increasing interest owing to its greater capacity retention in advanced solid-state lithium batteries (SSLBs), while suffers from severe interfacial instability during cycling. Here, via atomic layer deposition, Li3 PO4 is introduced to coat SC-NCM (L-NCM), to suppress undesired side reaction and enhance interfacial stability. The dynamic degradation and surface regulation of SC-NCM are investigated inside a working SSLB by in situ atomic force microscopy (AFM). We directly observe the uneven cathode electrolyte interphase (CEI) and surface defects on pristine SC-NCM particle. Remarkably, the formed amorphous LiF-rich CEI on L-NCM maintains its initial structure upon cycling, and thus endows the battery with improved cycling stability and excellent rate capability. Such on-site tracking provides deep insights into surface mechanism and structure-reactivity correlation of SC-NCM, and thus benefits the optimizations of SSLBs.

Revealing the High Salt Concentration Manipulated Evolution Mechanism on the Lithium Anode in Quasi-Solid-State Lithium-Sulfur Batteries.

Lithium-sulfur batteries are promising candidates of energy storage devices. Both adjusting salt/solvent ratio and applying quasi-solid-state electrolytes are regarded as effective strategies to improve the lithium (Li) anode performance. However, reaction mechanisms and interfacial properties in quasi-solid-state lithium-sulfur (QSSLS) batteries with high salt concentration are not clear. Here we utilize in-situ characterizations and molecular dynamics simulations to unravel aforesaid mysteries, and construct relationships of electrolyte structure, interfacial behaviour and performance. The generation mechanism, formation process, and mechanical/chemical/electrochemical properties of the anion-derived solid electrolyte interphase (SEI) are deeply explored. Li deposition uniformity and dissolution reversibility are further tuned by the sustainable SEI. These straightforward evidences and deepgoing studies would guide the electrolyte design and interfacial engineering of QSSLS batteries.

Dynamic Evolution of a Cathode Interphase Layer at the Surface of LiNi0.5Co0.2Mn0.3O2 in Quasi-Solid-State Lithium Batteries.

Intensive understanding of the surface mechanism of cathode materials, such as structural evolution and chemical and mechanical stability upon charging/discharging, is crucial to design advanced solid-state lithium batteries (SSLBs) of tomorrow. Here, via in situ atomic force microscopy monitoring, we explore the dynamic evolution process at the surface of LiNi0.5Co0.2Mn0.3O2 cathode particles inside a working SSLB. The dynamic formation process of the cathode interphase layer, with an inorganic-organic hybrid structure, was real-time imaged, as well as the evolution of its mechanical property by in situ scanning of the Derjaguin-Muller-Toporov modulus. Moreover, different components of the cathode interphase layer, such as LiF, Li2CO3, and specific organic species, were identified in detailat different stages of cycling, which can be directly correlated with the impedance buildup of the battery. In addition, the transition metal migration and the formation of new phases can further exacerbate the degradation of the SSLB. A relatively stable cathode interphase is key to improving the performance of SSLBs. Our findings provide deep insights into the dynamic evolution of surface morphology, chemical components and mechanical properties of the cathode interphase layer, which are pivotal for the performance optimization of SSLBs.

Interfacial Evolution of Lithium Dendrites and Their Solid Electrolyte Interphase Shells of Quasi-Solid-State Lithium-Metal Batteries.

Unstable electrode/solid-state electrolyte interfaces and internal lithium dendrite penetration hamper the applications of solid-state lithium-metal batteries (SSLMBs), and the underlying mechanisms are not well understood. Herein, in situ optical microscopy provides insights into the lithium plating/stripping processes in a gel polymer electrolyte and reveals its dynamic evolution. Spherical lithium deposits evolve into moss-like and branch-shaped lithium dendrites with increasing current densities. Remarkably, the on-site-formed solid electrolyte interphase (SEI) shell on the lithium dendrite is distinctly captured after lithium stripping. Inducing an on-site-formed SEI shell with an enhanced modulus to wrap the lithium precipitation densely and uniformly can regulate dendrite-free behaviors. An in-depth understanding of lithium dendrite evolution and its functional SEI shell will aid in the optimization of SSLMBs.

A Dynamically Stable Mixed Conducting Interphase for All-Solid-State Lithium Metal Batteries.

All-solid-state lithium (Li) metal batteries (ASSLMBs) employing sulfide solid electrolytes have attracted increasing attention owing to superior safety and high energy density. However, the instability of sulfide electrolytes against Li metal induces the formation of two types of incompetent interphases, solid electrolyte interphase (SEI) and mixed conducting interphase (MCI), which significantly blocks rapid Li-ion transport and induces uneven Li deposition and continuous interface degradation. In this contribution, a dynamically stable mixed conducting interphase (S-MCI) is proposed by in situ stress self-limiting reaction to achieve the compatibility of Li metal with composite sulfide electrolytes (Li6 PS5 Cl (LPSCl) and Li10 GeP2 S12 (LGPS)). The rational design of composite electrolytes utilizes the expansion stress induced by the electrolyte decomposition to in turn constrain the further decomposition of LGPS. Consequently, the S-MCI inherits the high dynamical stability of LPSCl-derived SEI and the lithiophilic affinity of Li-Ge alloy in LGPS-derived MCI. The Li||Li symmetric cells with the protection of S-MCI can operate stably for 1500 h at 0.5 mA cm-2 and 0.5 mAh cm-2 . The Li||NCM622 full cells present stable cycling for 100 cycles at 0.1 C with a high-capacity retention of 93.7%. This work sheds fresh insight into constructing electrochemically stable interphase for high-performance ASSLMBs.

In Situ Insight into the Interfacial Dynamics in "Water-in-Salt" Electrolyte-Based Aqueous Zinc Batteries.

Water-in-salt (WIS) electrolyte is considered as one of most promising systems for aqueous zinc batteries (AZBs) due to its dendrite-free plating/stripping with nearly 100% Coulombic efficiency. However, the understanding of the interfacial mechanisms remains elusive, which is crucial for further improvements in battery performance. Herein, the interfacial processes of solid electrolyte interphase (SEI) formation and subsequent Zn plating/stripping are monitored by in situ atomic force microscopy and in situ optical microscopy. The live formation of uniform and compact LiF-rich SEI in WIS systems could induce the uniform hexagonal Zn deposition with preferential orientation growth in the (002) crystal plane, showing excellent plating/stripping reversibility. In contrast, the SEI formed in 1 m zinc bis(trifluoromethylsulfonyl)imide (Zn(TFSI)2 ) is uneven and rich in inert ZnO, adversely triggering the dendrite propagation and successive "dead" Zn accumulation in repeated deposition/dissolution cycles. This work provides an in-depth understanding of the relationship between SEI evolution and Zn-deposited behaviors in AZBs, possibly stimulating more research on rational composition design and structural optimization of solid/liquid interface for advanced rechargeable aqueous multivalent-ion batteries.

Perioperative Exhaled Nitric Oxide as an Indicator for Postoperative Pneumonia in Surgical Lung Cancer Patients: A Prospective Cohort Study Based on 183 Cases.

Introduction: This study is conducted to investigate the correlation between perioperative fractional exhaled nitric oxide and postoperative pneumonia (POP) and the feasibility of perioperative FeNO for predicting POP in surgical lung cancer patients. Methods: Patients who were diagnosed with non-small-cell lung cancer (NSCLC) were prospectively analyzed, and the relationship between perioperative FeNO and POP was evaluated based on patients' basic characteristics and clinical data in the hospital. Results: There were 218 patients enrolled in this study. Finally, 183 patients were involved in the study, with 19 of them in the POP group and 164 in the non-POP group. The POP group had significantly higher postoperative FeNO (median: 30.0 vs. 19.0 ppb, P < 0.001) as well as change in FeNO (median: 10.0 vs. 0.0 ppb, P < 0.001) before and after the surgery. For predicting POP based on the receiver operating characteristic (ROC) curve, a cutoff value of 25 ppb for postoperative FeNO (Youden's index: 0.515, sensitivity: 78.9%, and specificity: 72.6%) and 4 ppb for change in FeNO (Youden's index: 0.610, sensitivity: 84.2%, specificity: 76.8%) were selected. Furthermore, according to the bivariate regression analysis, FEV1/FVC (OR = 0.948, 95% CI: 0.899-0.999, P=0.048), POD1 FeNO (OR = 1.048, 95% CI: 1.019-1.077, P=0.001), and change in FeNO (OR = 1.087, 95% CI: 1.044-1.132, P < 0.001) were significantly associated with occurrence of POP. Conclusions: This prospective study revealed that a high postoperative FeNO (>25 ppb), as well as an increased change in FeNO (>4 ppb), may have the potential in detecting the occurrence of POP in surgical lung cancer patients.

Value of Peak Expiratory Flow Rate in Evaluating Cough Ability in Patients Undergoing Lung Surgery.

Introduction: Postoperative ineffective cough is easy to occur after thoracic surgery, and it is also a risk factor for postoperative pulmonary complications (PPCs). Objectives: To explore the value of peak expiratory flow rate (PEF) in evaluating cough ability in patients undergoing lung surgery and evaluate the effectiveness of chest wall compression during the expiratory phase by PEF. Methods: From September 2020 to May 2021, the researchers collected the data of patients who underwent lung surgery. Eventually, 153 patients who met the criteria were included, 102 cases were included in the effective cough group and 51 cases were included in the ineffective cough group. The receiver working curve (ROC curve) was used to analyze whether PEF could evaluate cough ability. At the same time, the researchers collected the pulmonary function data of the first 30 patients of the ineffective cough group while compressing the chest wall during the expiratory phase to evaluate the effectiveness of chest wall compression. Results: The area under the curve (AUC) of postoperative PEF to evaluate the postoperative cough ability was 0.955 (95% CI: 0.927-0.983, P < 0.001). The values of PEF (127.17 ± 34.72 L/min vs. 100.70 ± 29.98 L/min, P < 0.001, 95% CI: 18.34-34.59) and FEV1 (0.72 (0.68-0.97) L vs. 0.64 (0.56-0.82) L, P < 0.001) measured while compressing the chest wall were higher than those without compression. Conclusions: PEF can be used as a quantitative indicator of cough ability. Chest wall compression could improve cough ability for patients who have ineffective cough.