Modeling and Design of All-Solid-State Batteries: From Materials to Interfaces

All-solid-state batteries show its great potential for being the next-generation source of clean energy barely with safety issues. While current research progress suggests the bottleneck of commercialization of all-solid-state batteries is the high resistivity at the electrode/SE interfaces. The aim of this thesis is to demonstrate how computational efforts can help understand and tackle the interface issues. The content comprises the following three projects: the methodology development (Chapter 2), the optimization of bulk materials (Chapter 3), and combined experimental and theoretical investigation into reactive interfaces (Chapter 4 & 5).In the first project, we aimed to develop and improve the computational workflow in material science research, especially those related to the interfaces. In the first part of this project, the Nudged Elastic Band (NEB) workflow has been developed with high automation and flexibility; and in the second part, an extension to a traditional molecular dynamics workflow specifically for tracking interface reactions has been implemented.The intrinsic properties of bulk materials are important to the interfacial properties and, thus, the performance of the full-cell battery. In the second project, we illustrated a computational aided design of bulk material, the Mg-doped Na3V2(PO4)3 cathode Na3+xV2-xMgx(PO4)3/C.The third project includes chapters 4 & 5, which are interfacial investigations on Na-ion and Li-ion, respectively. In chapter 4, we have demonstrated how thermodynamic approximations based on assumptions of fast alkali diffusion and multi-species equilibrium can be used to effectively screen combinations of Na-ion electrodes, solid electrolytes and buffer oxides for electrochemical and chemical compatibility. In addition to the thermodynamic approximation, ab initio molecular dynamics simulations of the NaCoO 2 /Na 3 PS 4 interface model predict that the formation of [SO4]2- -containing compounds and Na3P are kinetically favored over the formation of [PO4]3- -containing compounds, which has been validated through XPS recently. Chapter 5 investigate the source of reactivity between the sulfide solid electrolyte Li6PS5Cl (LPSCl) and the high-voltage cathode LiNi0.85Co0.1Al0.05O2 (NCA). And both experimental and computational results demonstrated improved stability between NCA and LPSCl after incorporation of the LiNbO 3 coating

Revealing Nanoscale Solid-Solid Interfacial Phenomena for Long-Life and High-Energy All-Solid-State Batteries.

Enabling long cyclability of high-voltage oxide cathodes is a persistent challenge for all-solid-state batteries, largely because of their poor interfacial stabilities against sulfide solid electrolytes. While protective oxide coating layers such as LiNbO3 (LNO) have been proposed, its precise working mechanisms are still not fully understood. Existing literature attributes reductions in interfacial impedance growth to the coating's ability to prevent interfacial reactions. However, its true nature is more complex, with cathode interfacial reactions and electrolyte electrochemical decomposition occurring simultaneously, making it difficult to decouple each effect. Herein, we utilized various advanced characterization tools and first-principles calculations to probe the interfacial phenomenon between solid electrolyte Li6PS5Cl (LPSCl) and high-voltage cathode LiNi0.85Co0.1Al0.05O2 (NCA). We segregated the effects of spontaneous reaction between LPSCl and NCA at the interface and quantified the intrinsic electrochemical decomposition of LPSCl during cell cycling. Both experimental and computational results demonstrated improved thermodynamic stability between NCA and LPSCl after incorporation of the LNO coating. Additionally, we revealed the in situ passivation effect of LPSCl electrochemical decomposition. When combined, both these phenomena occurring at the first charge cycle result in a stabilized interface, enabling long cyclability of all-solid-state batteries

Array atomic force microscopy for real-time multiparametric analysis.

Nanoscale multipoint structure-function analysis is essential for deciphering the complexity of multiscale biological and physical systems. Atomic force microscopy (AFM) allows nanoscale structure-function imaging in various operating environments and can be integrated seamlessly with disparate probe-based sensing and manipulation technologies. Conventional AFMs only permit sequential single-point analysis; widespread adoption of array AFMs for simultaneous multipoint study is challenging owing to the intrinsic limitations of existing technological approaches. Here, we describe a prototype dispersive optics-based array AFM capable of simultaneously monitoring multiple probe-sample interactions. A single supercontinuum laser beam is utilized to spatially and spectrally map multiple cantilevers, to isolate and record beam deflection from individual cantilevers using distinct wavelength selection. This design provides a remarkably simplified yet effective solution to overcome the optical cross-talk while maintaining subnanometer sensitivity and compatibility with probe-based sensors. We demonstrate the versatility and robustness of our system on parallel multiparametric imaging at multiscale levels ranging from surface morphology to hydrophobicity and electric potential mapping in both air and liquid, mechanical wave propagation in polymeric films, and the dynamics of living cells. This multiparametric, multiscale approach provides opportunities for studying the emergent properties of atomic-scale mechanical and physicochemical interactions in a wide range of physical and biological networks

2DMatPedia: An open computational database of two-dimensional materials from top-down and bottom-up approaches

Two-dimensional (2D) materials have been a hot research topic in the last decade, due to novel fundamental physics in the reduced dimension and appealing applications. Systematic discovery of functional 2D materials has been the focus of many studies. Here, we present a large dataset of 2D materials, with more than 6,000 monolayer structures, obtained from both top-down and bottom-up discovery procedures. First, we screened all bulk materials in the database of Materials Project for layered structures by a topology-based algorithm, and theoretically exfoliate them into monolayers. Then, we generated new 2D materials by chemical substitution of elements in known 2D materials by others from the same group in the periodic table. The structural, electronic and energetic properties of these 2D materials are consistently calculated, to provide a starting point for further material screening, data mining, data analysis and artificial intelligence applications. We present the details of computational methodology, data record and technical validation of our publicly available data (http://www.2dmatpedia.org/)

Correlation of sarcopenia and depressive mood in older community dwellers: a cross-sectional observational study in China

Objective Whether sarcopenia is detrimental to depression is still controversial, which may be due to the three components of the sarcopenia. Our objective was to define the correlation between depression and sarcopenia in older Chinese community dwellers.Design The study has a cross-sectional design.Setting The study was conducted in Jiangsu, China.Participants A total of 101 men and 149 women aged 60 years or older were recruited.Outcome measures Lean tissue mass was measured by dual-energy X-ray absorptiometry. Muscle strength in the upper and lower limbs was measured by a handheld dynamometer and a chair stand test, respectively. Physical performance was assessed by gait speed and standing balance tests. Depressive mood was assessed using the Geriatric Depression Scale-30 (range 0–30).Results Participants in the sarcopenia group had a higher mean depression score than the normal group (p=0.002). Pearson’s correlation analysis showed that depression was negatively associated with muscle strength (handgrip strength: R=−0.170, p=0.028 for women, R=−0.196, p=0.048 for men; chair stand test performance: R=0.252, p=0.002 for women, R=0.311, p=0.001 for men) and physical performance (gait speed: R=−0.200, p=0.009, standing balance test performance: R=−0.224, p=0.006, Short Physical Performance Battery (SPPB): R=−0.218, p=0.007 for women; SPPB: R=−0.252, p=0.01 for men). Multiple linear regression models revealed that depressive mood was inversely associated with chair stand test (β=0.325, p<0.001), gait speed (β=−0.009, p=0.041) and standing balance test (β=−0.24, p=0.016) after adjusting for confounding factors, while no significant correlation was observed between depressive mood and muscle mass.Conclusion The diagnostic components of sarcopenia—strength of the leg muscles (chair stand test) and physical performance (gait speed and standing balance test)—were associated with depressive mood

Knowledge, Attitude, and Practice of Adolescent Parents on Free Sugar and Influencing Factors about Recognition

Physiological problems caused by excessive intake of free sugar have been concerning important public health issues, especially the impact on adolescents. The World Health Organization (WHO) strongly recommends controlling daily sugar intake in order to reduce the stress caused by high sugar uptake. Finding out the factors that affect adolescents’ sugar intake will help further interventions to control the intake of sugar. Therefore, we conducted a cross-sectional study among 10 middle schools in Changsha, the capital of Hunan province. Two classes of the first and second grades were randomly selected from each school, and their parents in these classes participated in the survey. Questionnaires were used to access the status of adolescent parents’ knowledge, attitude and practice (KAP) towards free sugar. Out of 1136 valid participants, 70.4% of respondents were female with the mean (Standard Deviation) age of 41.76 (±5.27) years. They had a good attitude but relatively poor knowledge and behavior towards free sugar. Binary logistic regression analysis found that parents whose gender is female, with a high education level and a girl as their child, hold a high level of free sugar recognition. These findings could help free sugar control interventions for adolescents in the future

Maleimide-Functionalized Liposomes: Prolonged Retention and Enhanced Efficacy of Doxorubicin in Breast Cancer with Low Systemic Toxicity

Cell surface thiols can be targeted by thiol-reactive groups of various materials such as peptides, nanoparticles, and polymers. Here, we used the maleimide group, which can rapidly and covalently conjugate with thiol groups, to prepare surface-modified liposomes (M-Lip) that prolong retention of doxorubicin (Dox) at tumor sites, enhancing its efficacy. Surface modification with the maleimide moiety had no effect on the drug loading efficiency or drug release properties. Compared to unmodified Lip/Dox, M-Lip/Dox was retained longer at the tumor site, it was taken up by 4T1 cells to a significantly greater extent, and exhibited stronger inhibitory effect against 4T1 cells. The in vivo imaging results showed that the retention time of M-Lip at the tumor was significantly longer than that of Lip. In addition, M-Lip/Dox also showed significantly higher anticancer efficacy and lower cardiotoxicity than Lip/Dox in mice bearing 4T1 tumor xenografts. Thus, the modification strategy with maleimide may be useful for achieving higher efficient liposome for tumor therapy