chematic diagram of the cycling and Li deposition process

Major Contributions
 

1. A novel bifunctional protective layer composed of in-situ formed LiF-Li3Bi was introduced to stabilize the interface between Li6PS5Cl sulfide solid electrolyte and lithium metal. This interlayer, created by incorporating BiF3 powder into the solid electrolyte, simultaneously provides lithiophobic and lithiophilic functionalities, which effectively suppress lithium dendrite growth and enhance interfacial stability.

2. The in-situ generated Li3Bi-LiF hybrid layer significantly improves lithium-ion transport and uniform deposition at the interface. Li3Bi, with its high lithiophilicity and low diffusion energy barrier, ensures even electric field distribution and rapid Li+ transfer, while LiF, with high interface energy, impedes dendrite penetration. This synergy results in reduced interfacial impedance and improved cycling performance.

3. The proposed approach demonstrated outstanding electrochemical performance in both symmetric and full-cell configurations. Lithium symmetric cells with the bifunctional interlayer achieved a remarkable critical current density of 14 mA cm⁻² and stable cycling for over 1000 hours. In full cells, capacity retention was dramatically enhanced to 90.01%, compared to 55.86% for cells without the interlayer, confirming the effectiveness of the in-situ formed SEI for advancing all-solid-state lithium batteries.

主要貢獻
 

1. 提出一種新型雙功能保護層，藉由在Li6PS5Cl硫化物固態電解質中摻入BiF3粉末，於鋰金屬界面原位生成LiF-Li3Bi混合層。此層同時具備疏鋰性與親鋰性，有效抑制鋰枝晶生長並提升界面穩定性。

2. 原位生成的Li3Bi-LiF混合層大幅提升界面鋰離子傳輸與均勻沉積。Li3Bi具高親鋰性及低擴散能障，促進均勻電場分布與快速Li+遷移；LiF則因高界面能有效阻止枝晶穿透。兩者協同作用，降低界面阻抗並提升循環性能。

3. 此創新策略於對稱電池與全電池測試中展現卓越電化學性能。具雙功能界面的鋰對稱電池達到14 mA cm⁻²的臨界電流密度，並於室溫下穩定循環超過1000小時；全電池容量保持率提升至90.01%，遠優於無界面層的55.86%，證實原位生成SEI對提升全固態鋰電池性能之關鍵作用。