In the quest for safer, high-energy-density batteries, solid-state lithium metal batteries (SSLMBs) have emerged as a promising contender. However, their path to commercialization is fraught with challenges, particularly the growth of lithium dendrites that can cause short circuits. A recent study published in the journal “Small Structures” (formerly known as “Small Methods”) sheds new light on how the porosity of solid-state electrolytes influences these dendrites, offering valuable insights for the energy sector.
Led by Shuangquan Lin from the National Power Battery Innovation Center at GRINM Group Co. Ltd. in Beijing, the research team investigated the impact of electrolyte film porosity on lithium metal nucleation and dendrite formation. Their findings, while counterintuitive, reveal that increased porosity enhances electronic conductivity, facilitating dendrite formation. “We found that increased surface exposure through porosity reduces the bandgap, enhancing electronic conductivity,” Lin explains. This increased conductivity, in turn, promotes the formation of lithium dendrites, which are undesirable as they can lead to battery failure.
The study employed Density Functional Theory calculations to understand the surface and bulk phase of the electrolyte and the spacing between electrolyte particles. Electrochemical simulations further demonstrated that pores create a non-uniform distribution of lithium-ion concentration, current density, and electric potential field within the electrolyte. These findings suggest that a trade-off exists between enhancing ionic conductivity and maintaining mechanical strength and interfacial contact.
From a commercial perspective, these insights are invaluable. The energy sector is keenly interested in SSLMBs due to their potential for higher energy density and improved safety. However, the challenge of dendrite formation has hindered their widespread adoption. This research provides a deeper understanding of the role of porosity in electrolyte films, which could guide the design of future SSLMBs.
The study also highlights the importance of balancing porosity to achieve optimal performance. While increased porosity enhances electronic conductivity, it also promotes dendrite formation. Therefore, finding the right balance is crucial for developing high-performance SSLMBs. “Our experimental results demonstrate that electrolyte films with lower porosity exhibit higher limiting current and superior electrochemical performance,” Lin notes. This suggests that minimizing porosity could be a strategy to mitigate dendrite formation and improve battery performance.
As the energy sector continues to evolve, research like this plays a pivotal role in shaping the future of battery technology. By unraveling the complexities of electrolyte porosity, this study paves the way for the development of more efficient and safer solid-state lithium metal batteries. The insights gained could accelerate the commercialization of SSLMBs, bringing us one step closer to a future powered by high-energy-density, safe, and reliable batteries.