The Role of Electrolyte Additives in Mitigating Dendrite Growth and Improving Battery Cycle Performance

Dendrite growth, a common issue in lithium-metal-based batteries, can lead to internal short-circuiting between electrodes and poor battery cycle performance. Uncontrolled dendrite formation, large volume changes, and irreversible electrolyte degradation reactions are inherent problems that hinder the practical application of lithium metal anodes in portable electronics. Despite its excellent electrochemical properties, lithium metal's long-standing issues remain a major concern.

One potential solution to mitigate dendrite growth is the use of electrolyte additives. Hydrogen fluoride (HF) has been identified as a promising additive that can form a protective film on the anode surface, suppressing large interphase volume changes and unnecessary degradation reactions. This film helps to prevent the growth of dead lithium and dendrites during repeated charging.

To investigate this mechanism, a series of reactive molecular dynamics (MD) simulations were performed to study the electrochemical dynamic reactions at the electrode/electrolyte interface. The results showed that beneficial decomposition reactions between electrolyte components form a protective film on the anode surface, which suppresses large interphase volume changes and unnecessary degradation reactions.

In this study, we utilized a computational protocol to investigate the dendrite mitigation mechanism when HF is dissolved in an organic ethylene carbonate (EC) electrolyte solvent. The protocol allowed for quantitative characterization of morphological phenomena and real-time interfacial visualization of the dynamic growth of dead lithium and dendrites during repeated charging.

Our findings suggest that the addition of HF to the electrolyte can significantly reduce dendrite growth and improve battery cycle performance. This is because HF forms a protective film on the anode surface, which prevents the growth of dead lithium and dendrites. The results of this study demonstrate the potential of electrolyte additives in mitigating dendrite growth and improving the performance of lithium-metal-based batteries.

In conclusion, the use of electrolyte additives such as hydrogen fluoride can help to mitigate dendrite growth and improve battery cycle performance. Further research is needed to fully understand the interfacial mechanism of lithium dendrite growth and to develop more effective strategies for mitigating this issue. However, our study provides valuable insights into the role of electrolyte additives in improving the performance of lithium-metal-based batteries and highlights their potential as a solution to the long-standing problems associated with lithium metal anodes.