Field-Assisted Regulation Induced by Cobalt-Doped ZnO for Dendrite-Free Lithium Metal Anodes

Lithium metal batteries are deemed as an optimal candidate for the next generation of durable energy storage devices. However, the growth of lithium dendrite and significant volume expansion pose as obstacles that impede the application of lithium metal batteries. In this work, a functional copper current collector was designed by coating it with Co-doped ZnO (Co/ZnO) to enhance the lithiophilicity through local electric fields and built-in magnetic fields induced by the ferromagnetic material. The incorporation of Co not only induces a local electric field and thus accelerating electron transfer, but also imparts the ferromagnetic behavior to ZnO, resulting in an internal magnetic field to regulate the dynamic trajectory. Profiting from the above advantages, the symmetric cells have excellent cycle stability in 1 mA cm-2 and 1 mAh cm-2 , maintaining ultra-low voltage for over 2000 h. This study provides a realizable pathway for next-generation current collector of copper modification.

Quantification of the Dynamic Interface Evolution in High-Efficiency Working Li Metal Batteries

Lithium (Li) metal has been considered a promising anode for next-generation high-energy-density batteries. However, the low reversibility and intricate Li loss hinder the widespread implement of Li metal batteries. Herein, we quantitatively differentiate the dynamic evolution of inactive Li, and decipher the fundamental interplay among dynamic Li loss, electrolyte chemistry, and the structure of solid electrolyte interphase (SEI). The actual domination form in inactive Li loss is practically determined by the relative growth rates of dead Li0 and SEI Li+ because of the persistent evolving of Li metal interface during cycling. Distinct inactive Li evolution scenarios are disclosed when ingeniously tuning the inorganic anion-derived SEI chemistry with low amount of film-forming additive. An optimal polymeric film enabler of 1,3-dioxolane is demonstrated to derive a highly uniform multilayer SEI and declined SEI Li+/dead Li0 growth rates, thus achieving enhanced Li cycling reversibility.

Non-Solvating and Low-Dielectricity Cosolvent for Anion-Derived Solid Electrolyte Interphases in Lithium Metal Batteries

Lithium (Li) metal anodes hold great promise for next-generation high-energy-density batteries, while the insufficient fundamental understanding of the complex solid electrolyte interphase (SEI) is the major obstacle for the full demonstration of their potential in working batteries. The characteristics of SEI highly depend on the inner solvation structure of lithium ions (Li⁺ ). Herein, we clarify the critical significance of cosolvent properties on both Li⁺ solvation structure and the SEI formation on working Li metal anodes. Non-solvating and low-dielectricity (NL) cosolvents intrinsically enhance the interaction between anion and Li⁺ by affording a low dielectric environment. The abundant positively charged anion-cation aggregates generated as the introduction of NL cosolvents are preferentially brought to the negatively charged Li anode surface, inducing an anion-derived inorganic-rich SEI. A solvent diagram is further built to illustrate that a solvent with both proper relative binding energy toward Li⁺ and dielectric constant is suitable as NL cosolvent.