Peichen Zhong

University of California, Berkeley | UCB · Department of Materials Science and Engineering

Large-scale simulations with complex electron interactions remain one of the greatest challenges for atomistic modelling. Although classical force fields often fail to describe the coupling between electronic states and ionic rearrangements, the more accurate ab initio molecular dynamics suffers from computational complexity that prevents long-time...

Modern battery materials can contain many elements with substantial site disorder, and their configurational state has been shown to be critical for their performance. The intercalation voltage profile is a critical parameter to evaluate the performance of energy storage. The application of commonly used cluster expansion techniques to model the in...

We introduce ℓ0ℓ2-norm regularization and hierarchy constraints into linear regression for the construction of cluster expansions to describe configurational disorder in materials. The approach is implemented through mixed integer quadratic programming (MIQP). The ℓ2-norm regularization is used to suppress intrinsic data noise, while the ℓ0-norm is...

Disordered rocksalt oxide (DRX) cathodes are promising candidates for next-generation Co- and Ni-free Li-ion batteries. While fluorine substitution for oxygen has been explored as an avenue to enhance their performance, the amount of fluorine incorporated into the DRX structure is particularly challenging to quantify and impedes our ability to rela...

Modern battery materials can contain many elements with substantial site disorder, and their configurational state has been shown to be critical for their performance. The intercalation voltage profile is a critical parameter to evaluate the performance of energy storage. The application of commonly used cluster expansion techniques to model the in...

Artificial intelligence (AI) has emerged as a powerful tool in the discovery and optimization of novel battery materials. However, the adoption of AI in battery cathode representation and discovery is still limited due to the complexity of optimizing multiple performance properties and the scarcity of high-fidelity data. In this study, we present a...

The simulation of large-scale systems with complex electron interactions remains one of the greatest challenges for the atomistic modeling of materials. Although classical force-fields often fail to describe the coupling between electronic states and ionic rearrangements, the more accurate \textit{ab-initio} molecular dynamics suffers from computat...

Hollow metal chalcogenide nanoparticles are widely applicable in environmental and energy-related processes. Herein, we synthesized such particles with large compositional and morphological diversity by combining scanning probe block copolymer lithography with a Kirkendall effect-based sulfidation process. We explored the influence of temperature-d...

Li‐excess disordered rocksalts (DRXs) are emerging as promising cathode materials for Li‐ion batteries due to their ability to use earth‐abundant transition metals. In this work, a new strategy based on partial Li deficiency engineering is introduced to optimize the overall electrochemical performance of DRX cathodes. Specifically, by using Mn‐base...

Li‐rich rocksalt oxides are promising cathode materials for lithium‐ion batteries due to their large capacity and energy density, and their ability to use earth‐abundant elements. The excess Li in the rocksalt, needed to achieve good Li transport, reduces the theoretical transition metal redox capacity and introduces a labile oxygen state, both of...

The cluster expansion (CE) method has seen continuous and increasing use in the study of configuration-dependent properties of crystalline materials. The original development of the CE method along with the underlying mathematical formalism and assumptions was focused on the study of metallic alloys. Since then the methodology has been actively and...

Monte-Carlo sampling of lattice model Hamiltonians is a well-established technique in statistical mechanics for studying the configurational entropy of crystalline materials. When species to be distributed on the lattice model carry charge, the charge balance constraint on the overall system prohibits single-site Metropolis exchanges in MC. In this...

We introduce the $\ell_0\ell_2$-norm regularization and hierarchy constraints into linear regression for the construction of cluster expansion to describe configurational disorder in materials. The approach is implemented through mixed integer quadratic programming (MIQP). The $\ell_2$-norm regularization is used to compress intrinsic data noise, w...

High-rate cathode materials for Li-ion batteries require fast Li transport kinetics, which typically rely on topotactic Li intercalation/de-intercalation because it minimally disrupts Li transport pathways. In contrast to this conventional view, here we demonstrate that the rate capability in a Li-rich cation-disordered rocksalt cathode can be sign...

Using both computations and experiments, we demonstrate that the performance of Li-excess cation-disordered rocksalt cathodes can be improved by Mg substitution. Mg reduces the amount of Li in the compound that is strongly bound to F and thereby increases the capacity. This enables the use of fluorination as a tool to improve stability of the compo...

The discovery of Li-excess cation-disordered rocksalt (DRX) cathodes greatly enlarges the design space beyond the layered NCM-type rocksalt chemistries. Fluorination of DRX cathodes can provide more capacity by reducing the transition metal valence and reduce oxygen loss by protecting the surface. On the other hand, fluorine’s strong bonding with l...

We theoretically demonstrate that the in-plane magnetization induced quantum anomalous Hall effect (QAHE) can be realized in atomic crystal layers of group-V elements with buckled honeycomb lattice. We first construct a general tight-binding Hamiltonian with $sp^3$ orbitals via Slater-Koster two-center approximation, and then numerically show that...