Qingsong Tu

Qingsong Tu
University of California, Berkeley | UCB · Department of Civil and Environmental Engineering

PhD student

About

31
Publications
6,087
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1,056
Citations

Publications

Publications (31)
Article
Full-text available
The key component in lithium solid‐state batteries (SSBs) is the solid electrolyte composed of lithium superionic conductors (SICs). Lithium oxide SICs offer improved electrochemical and chemical stability compared with sulfides, and their recent advancements have largely been achieved using materials in the garnet‐ and NASICON (sodium superionic c...
Article
Full-text available
Metal penetration into a solid electrolyte (SE) is one of the critical problems impeding the practical application of solid-state batteries. In this study, we investigate the conditions under which electronic conductivity of the SE can lead to metal deposition and fracture within the SE. Three different stages for void filling (metal plating initia...
Article
Autonomous synthesis and characterization of inorganic materials require the automatic and accurate analysis of X-ray diffraction spectra. For this task, we designed a probabilistic deep learning algorithm to identify complex multi-phase mixtures. At the core of this algorithm lies an ensemble convolutional neural network trained on simulated diffr...
Preprint
Full-text available
Autonomous synthesis and characterization of inorganic materials requires the automatic and accurate analysis of X-ray diffraction spectra. For this task, we designed a probabilistic deep learning algorithm to identify complex multi-phase mixtures. At the core of this algorithm lies an ensemble convolutional neural network trained on simulated diff...
Article
Point-of-use (POU) devices with satisfactory lead (Pb2+) removal performance are urgently needed in response to recent outbreaks of lead contamination in drinking water. This study experimentally demonstrated the excellent lead removal capability of two-dimensional (2D) MoS2 nanosheets in aqueous form and as part of a layer-stacked membrane. Among...
Article
Solid-state batteries (SSBs) are considered promising next-generation energy storage devices but tend to suffer from rapid capacity fade. Here, we demonstrate that mechanical contact loss between the solid conductor and cathode, induced by its volume changes during cycling, plays a significant role in the observed capacity fade. Focused ion beam-sc...
Article
Full-text available
Interfacial deposition stability between lithium metal and a solid electrolyte (SE) is important in preventing interfacial contact loss, mechanical fracture, and dendrite growth in Li-metal solid-state batteries (SSBs). In this work, we investigate the deposition and mechanical stability at the Li-metal/SE interface and its consequences (such as SE...
Article
Full-text available
In this work, we systematically study a rotational nanofluidic device for reverse osmosis (RO) desalination by using large scale molecular dynamics modeling and simulation. Moreover, we have compared Molecular Dynamics simulation with fluid mechanics modeling. We have found that the pressure generated by the centrifugal motion of nanofluids can cou...
Article
Full-text available
Membranes synthesized by stacking two-dimensional graphene oxide (GO) hold great promise for applications in organic solvent nanofiltration. However, the performance of a layer-stacked GO membrane in organic solvent nanofiltration can be significantly affected by its swelling and interlayer spacing, which have not been systematically characterized....
Article
Full-text available
The use of inorganic solid-ionic conductors with a metal electrode, has been proposed as a way to increase energy density, decrease capacity loss and prevent failure from metal propagation. Current observations of Li-metal electrodes causing cell shorting in solid-state systems have been identified as main obstacles limiting the development of this...
Article
In article number 1902881, Gerbrand Ceder and co‐workers demonstrate that the active material loading in all‐solid‐state batteries is largely controlled by the active material and solid electrolyte particle size ratio. A generalized guideline is provided for increasing active material loading via particle size optimization, and a composite cathode...
Article
Full-text available
Low active material loading in the composite electrode of all‐solid‐state batteries (SSBs) is one of the main reasons for the low energy density in current SSBs. In this work, it is demonstrated with both modeling and experiments that in the regime of high cathode loading, the utilization of cathode material in the solid‐state composite is highly d...
Preprint
Interfacial deposition stability between Li metal and a solid electrolyte (SE) is important in preventing interfacial contact loss, mechanical fracture, and dendrite growth in Li-metal solid-state batteries (SSB). In this work, we investigate the deposition and mechanical stability at the Li metal/SE interface and its consequences (such as SE fract...
Article
Micromechanical loading events such as pop-in and indentation size effect (ISE) are well understood at room temperature and have been widely accepted as fundamental factors in the study of material mechanics at the microscale. Experimentally it has been observed that such phenomena can be greatly affected by temperature, but quantitative studies of...
Article
Two-dimensional materials such as graphene and carbon nanotube have promising applications in the preparation of permeable membranes and the field of environmental protection due to their unique structures and components. This paper conducts a study on graphene and nanotubes in salt solution using molecular dynamics computational method, and ascert...
Article
Layer-stacked graphene oxide (GO) membranes, in which unique two-dimensional (2D) water channels are formed between two neighboring GO nanosheets, have demonstrated great potential for aqueous phase separation. Subjects of crucial importance are to fundamentally understand the interlayer spacing (i.e., channel height) of GO membranes in aqueous env...
Article
Full-text available
A scale-up nanoporous membrane centrifuge is designed and modeled. It can be used for nanoscale scale separation including reverse osmosis desalination. There are micron-size pores on the wall of the centrifuge and nanoscale pores on local graphene membrane patches that cover the micron-size pores. In this work, we derived the critical angular velo...
Article
Full-text available
In this work, molecular dynamics (MD) and molecular mechanics (MM) simulations are used to study well-equilibrated models of 4,4′-bis(3,4-dicyanophenoxy)biphenyl (BPh)–1,3-bis(3-aminophenoxy)benzene (m-APB) phthalonitrile (PN) system with a range of crosslink densities. A cross-linking technique is introduced to build a series of systems with diffe...
Article
Full-text available
Membranes made of layer-stacked two-dimensional molybdenum disulfide (MoS2) nanosheets have recently shown great promise for water filtration. At present, the reported water fluxes vary significantly while the accountable structure and properties of MoS2 nanochannels are largely unknown. This paper aims to mechanistically relate the performance of...
Article
A concept of the porous graphene membrane centrifuge is proposed aiming at fabrication of large scale, fouling-free desalination machine with nanomaterial-based reverse osmosis modules. The concept as well as strategy of such porous rotating graphene membrane device is approved through molecular dynamics (MD) modeling and simulation of a nano-fluid...
Article
This work presents the novel application of hydrocyclones for mixed liquor recirculation (MLR) treatment in the anoxic/aerobic (A/O) process to enhance the denitrification process. An exhaustive investigation on treated activated sludge and A/O effluents was conducted in batch and continuous operation tests. The median diameter of the sludge flocs...
Article
Graphene oxide (GO) has recently emerged as a promising 2D nanomaterial to make high-performance membranes for important applications. However, the aqueous-phase separation capability of a layer-stacked GO membrane can be significantly limited by its natural tendency to swell, that is, absorb water into the GO channel and form enlarged interlayer s...
Article
Full-text available
We have designed a porous nanofluidic desalination device, a rotating carbon nanotube membrane filter (RCNT-MF), for the reverse osmosis desalination that can turn salt water into fresh water. The concept as well as design strategy of RCNT-MF is modeled, and demonstrated by using molecular dynamics simulation. It has been shown that the RCNT-MF dev...
Article
In this work, the Eshelby tensor of a finite spherical domain is employed to construct an interphase model to evaluate elastic properties of concrete composites. Explicit formulations of the interphase model via multi-inclusion method for a class of concrete composites are derived. The theoretical estimate based on an improved Hashin–Shtrikman boun...
Article
In this work, the interphase effects of nanoparticle enhanced polymer composite materials are investigated. Three interphase models based on finite size representative volume element (RVE) are proposed to estimate the effective material properties of nanoparticle-polymer composites, including" (1) The finite Eshelby tensor based shell model, (2) An...
Article
In this paper, we present molecular dynamics simulations of diffusion of Na + , K + , and Cl − ions through the single-walled carbon nanotubes(SWCNTs) that are embedded into the membrane of cells in aqueous solutions. A simplified atomic cell model that considers bilayer membranes is employed to study the transportation of ions inside CNTs. The sim...
Article
Full-text available
The relations between stresses and leakage magnetic signal of concentration area of the airplane's landing gear under varying load were studied. The finite element method was used to calculate the stress of axle under different conditions; An experiment was designed to simulate the stress status under the bending moment, the slight magnetic signals...

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