The state-of-the-art pellet type sodium solid-state batteries (NaSSBs) suffer from inadequate humidity stability and poor mechanical properties, resulting in non-negligible ohmic losses, limited crucial current density, and low energy density. To address these challenges, a dry process was proposed to fabricate Na₃PS₄ (NPS) film with only 0.2 wt % polytetrafluoroethylene (PTFE) binders. The density functional theory results revealed that PTFE with hydrophobic groups improves the moisture stability by reducing the available adsorption sites for H₂O on the surface. Furthermore, NaSSBs comprising an NPS film and NaCrO₂ (NCO) cathode exhibited a high specific discharge capacity of 119.6 mAh·g^–1 with an initial Coulombic efficiency (ICE) of 99.33%. After 24-h exposure of NPS film to a dry room (RH, 0.1%), a high conductivity retention of 90% and stable cycling can be achieved for 100 cycles with a capacity retention of 83.5%, representing a significant advancement toward scaling up and practical application of NaSSBs.

中文翻译：

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Na3PS4 固态电解质干膜的见解：界面稳定性和干燥室兼容性

最先进的颗粒型钠固态电池（NaSSB）存在湿度稳定性不足和机械性能差的问题，导致不可忽略的欧姆损耗、有限的关键电流密度和低能量密度。为了解决这些挑战，提出了一种干法工艺来制造仅含 0.2 wt% 聚四氟乙烯 (PTFE) 粘合剂的Na ₃ PS ₄ (NPS) 薄膜。密度泛函理论结果表明，具有疏水基团的PTFE通过减少表面上H ₂ O的可用吸附位点来提高水分稳定性。此外，包含NPS薄膜和NaCrO _{2 (NCO)正极的NaSSB表现出119.6 mAh·g} ^–1的高比放电容量，初始库仑效率(ICE)为99.33%。 NPS 薄膜在干燥室（相对湿度，0.1%）中暴露 24 小时后，可实现 90% 的高电导率保持率和 100 个循环的稳定循环，容量保持率为 83.5%，这代表着在规模化方面取得了重大进展NaSSBs的研究与实际应用