Dynamic observation of dendrite growth on lithium metal anode during battery charging/discharging cycles

Abstract

Lithium metal is considered one of the most promising anode materials for application in next-generation batteries. However, despite decades of research, practical application of lithium metal batteries has not yet been achieved because the fundamental interfacial mechanism of lithium dendrite growth is not yet fully understood. In this study, a series of reactive molecular dynamics (MD) simulations was performed to investigate the electrochemical dynamic reactions at the electrode/electrolyte interface. It allows quantitative characterization of morphological phenomena and real-time interfacial visualization of the dynamic growth of dead lithium and dendrites during repeated charging. This computational protocol was utilized to investigate the dendrite mitigation mechanism when an electrolyte additive (hydrogen fluoride) is dissolved in an organic ethylene carbonate (EC) electrolyte solvent. It was confirmed that beneficial decomposition reactions between electrolyte components form a protective film on the anode surface, suppressing large interphase volume changes and unnecessary degradation reactions.

Machine learning-inspired battery material innovation

“…Key properties such as lithium dendrite growth and SEI formations can be studied. [115][116][117][118] Moreover, kinetic Monte Carlo (KMC) and phase field methods can be used to study the degraded morphology and phase separations of electrodes at the microstructural level. 119,120 In addition, a pseudo 2D (P2D) model 121,122 at the continuum level can be used to study cell properties with degraded battery cell parameters.…”

Operando safety diagnosis for Li-ion battery via MHz band electromagnetics

“…Additional research in this field has a potential to reveal unexplored LiB applications. One potential is to diagnose internal shorting risks, known as dendritic-type Li-metal deposition 48,49 . Before internal short status, the growth of the dendrites will decreases the insulating distance between the positive and negative electrodes.…”

Constant-potential molecular dynamics simulation and its application in rechargeable batteries

“…7, Li dendrite growth and SEI evolution were modeled together for a Li metal battery for the first time. 52 ReaxFF 76 was used to change the atomic connectivity, and QEq 51 was used to model the charge transfer. The electrode potential was applied by modifying the electronegativities, and the potential propagates along the electrode according to electrochemistry dynamics with implicit degrees of freedom (EChemDID).…”

“…Specifically, HF additive in EC can effectively suppress the growth of Li dendrite and the occurrence of dead Li. 52 Meanwhile, the addition of HF also suppresses the decomposition of EC. After 20 charging–discharging cycles, 21.0% of the EC molecules were consumed in the simulation cell without the addition of HF, but only 14.7% of the EC molecules were consumed with HF added.…”