Do Youb Kim

All-solid-state Li-metal batteries (ASSLBs) are promising for next-generation energy storage systems owing to their high energy density and intrinsic safety. However, their practical applications are impeded by challenges such as low ionic conductivity, uncontrolled Li-dendrite growth, and interfacial instability. This study presents a scalable strategy to address these limitations by incorporating ferroelectric BaTiO₃ into poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) nanowebs. The 3D nanowebs were utilized to prepare composite solid polymer electrolytes (3DCSPEs), which exhibited significantly higher ionic conductivity (8.5 × 10^-4 S cm^-1 at 25 °C) and a higher Li-ion transference number (0.78) than a PVDF-HFP-based solid polymer electrolyte (PSPE). The 3DCSPEs effectively regulated Li-ion flux, suppressed dendrite growth, and stabilized interfacial contact. In battery tests, LiNi_0.8Mn_0.1Co_0.1O₂ (NCM811)/3DCSPE/Li cells outperformed conventional NCM811/PSPE/Li cells, exhibiting a higher capacity (143.72 mA h g^-1 at 0.1 C) and superior prolonged cycle stability over 600 cycles at 0.2 C at 25 °C. Additionally, 3DCSPE mitigated cathode cracking and enhanced ion transport, demonstrating its potential to advance Li polymer battery technology. This study clarifies the pivotal role of in situ cross-linked ferroelectric 3D nanowebs as a novel approach for addressing the key challenges in ASSLBs, facilitating the development of advanced Li polymer batteries.

Lithium (Li) metal is widely acknowledged as the most promising anode material, owing to its high capacity and low potential. However, the practical implementation of Li faces challenges, including uncontrollable dendritic growth and a deficient solid electrolyte interphase (SEI). Here a straightforward method is provided for fabricating Li composites using Al‐doped Li₇La₃Zr₂O₁₂ particles (Li/LLZO) with high Li‐ion conductivity achieved using a mechanical kneading process. The optimized composite, with 20% LLZO content (Li/LLZO‐20), effectively regulates the Li‐ion flux, successfully suppressing Li dendritic growth. Using a systematic investigation, it is demonstrated that incorporating LLZO particles significantly accelerates Li‐ion migration at the electrode–electrolyte interface, facilitating smooth transport through the LLZO particles. Consequently, Li‐metal battery and Li–S battery cells utilizing the Li/LLZO‐20 composite anode exhibit remarkable cycle stability compared to cells employing pure Li anodes.

For stable lithium deposition without dendrites, three-dimensional (3D) porous structure has been intensively investigated. Here, we report the use of carbon-doped graphitic carbon nitride (C-doped g-C₃N₄) microspheres as a 3D host for lithium to suppress dendrite formation, which is crucial for stable lithium deposition. The C-doped g-C₃N₄ microspheres have a high surface area and porosity, allowing for efficient lithium accommodation with high accessibility. The carbon-doping of the g-C₃N₄ microspheres confers lithiophilic properties, which facilitate the regulation of Li⁺ flux and dense filling of cavities with nucleated lithium, thereby preventing volume expansion and promoting dendrite-free Li deposition. The electrochemical performance was improved with cyclic stability and high Coulombic efficiency over 260 cycles at 1.0 mA cm⁻² for 1.0 mAh cm⁻², and even over 70 cycles at 5.0 mA cm⁻² for 3.0 mAh cm⁻². The use of C-doped g-C₃N₄ microspheres as a 3D Li host shows promising results for stable lithium deposition without dendrite formation.