In a significant stride towards enhancing solid-state sodium battery technology, researchers have introduced a novel approach to address long-standing challenges of ionic conductivity and interface stability. The study, published in the journal Advanced Science, presents a robust strategy for engineering flexible ferroelectric composite electrolytes, promising substantial improvements for compact solid-state sodium batteries (SSBs).
The research, led by Yanan Huang from the Volta and DiPole Materials Labs at Soochow University, focuses on the development of metaferroelectrolytes. These materials leverage strongly coupled intrinsic ion conducting 2D/2D sodium-rich anti-perovskite (NaRAP)/ferroelectric perovskite heterostructures. The team reported the creation of highly scalable PVDF-based metaferroelectrolytes, incorporating Na2.99Ba0.005OCl/Ca2Na2Nb5O16− (CNNO−) nanosheets into a ferroelectric poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) matrix.
The innovative approach utilizes an in situ cross-linking and spontaneous bridging method, resulting in a unique 3D ferroelectric coupled network. This network, induced by the Na2.99Ba0.005OCl/CNNO− nanosheets, regulates the Na+ flux, effectively inhibiting Na dendrite growth at the interface. The optimized PH-5% NC metaferroelectrolyte demonstrates rapid ion transport, a wide electrochemical window, superior mechanical compatibility, and enhanced flexibility, elasticity, and flame retardancy.
“Our metaferroelectrolyte exhibits remarkable properties, including rapid ion transport and a wide electrochemical window, which are crucial for the performance of solid-state sodium batteries,” said Yanan Huang, lead author of the study. “The stable cycling performance, even at low temperatures, makes this technology particularly promising for practical applications.”
The solid-state Na3V2(PO4)3/PH-5% NC/Na batteries developed in this research showcase stable cycling performance, retaining 56.4 mAh g−1 after 500 cycles at 1 C, even at 0 °C. This breakthrough offers a potential for cost-effective, safe, stable, and compact SSB energy storage with an energy density surpassing 600 Wh L−1, significantly outperforming the current commercial sodium-ion liquid-electrolyte batteries, which offer around 365 Wh L−1.
The implications of this research are far-reaching for the energy sector. The enhanced performance and stability of these solid-state sodium batteries could revolutionize energy storage solutions, making them more reliable and efficient. The technology’s potential for cost-effectiveness and safety further amplifies its commercial impact, paving the way for widespread adoption in various applications.
“This research not only advances our understanding of ferroelectric composite electrolytes but also opens new avenues for developing high-performance solid-state sodium batteries,” added Huang. “The potential for cost-effective and stable energy storage solutions is a game-changer for the energy sector.”
As the world continues to seek sustainable and efficient energy solutions, this breakthrough in solid-state sodium battery technology represents a significant step forward. The research published in Advanced Science (translated from German as “Advanced Science”) underscores the importance of innovative materials and methodologies in shaping the future of energy storage.