Phase-regulated ultrathin PVDF-based electrolytes for dynamic dendrite suppression in solid-state lithium metal batteries

作者：Haihua Luo, Jianhui Du, Jingjing Fu, Qing Zhang, Xinfang Hu, Bo Liu, Wenhua Zhang · 发表于：Nano Research · 年份：2025 · DOI：10.26599/nr.2025.94907631 · 被引用次数：7 · 研究领域：Advancements in Battery Materials、Advanced Battery Materials and Technologies、Advanced Battery Technologies Research

The pursuit for safer batteries has driven significant research efforts toward solid-state lithium metal cells. To achieve an energy density comparable to that of liquid electrolyte-based cells, the development of ultrathin and lightweight solid electrolytes with superior performance is essential. However, fabricating solid electrolytes with thicknesses comparable to those of commercial separators (~10 μm) used in liquid systems remains challenging because of the increased risk of short circuits caused by dendrite growth. In this study, we present a polymer-based solid-state electrolyte composed of a 7.3-μm-thick ultrathin poly(vinylidene fluoride) (PVDF) film embedded with highly oriented Ti 3 C 2 T x nanoflakes. Functionalized nanoflakes induce PVDF β-phase formation through hydrogen bonding, significantly improving dielectric and piezoelectric properties. These improvements enable a Li + -transfer number of 0.83 and ∼10-fold enhancement in piezoelectric response. A high Li + -transfer number reduces polarization by suppressing space-charge formation during Li plating. Simultaneously, when the electrolyte senses strain accumulation from inevitable Li protrusions, the piezoelectric-induced electric field promptly alleviates the localized overpotential, dynamically promoting uniform Li deposition. Consequently, these electrolytes exhibit exceptional compatibility with Li anode, enabling long-term cycling under various conditions. The symmetric Li||Li cells demonstrate stable...