磷/碳负极材料的空隙结构设计与复合界面重构及储钾机制研究

磷，储量丰富且价格低廉，能与多个钾离子发生合金反应，呈现极高理论容量与能量密度，但储钾性能仍受制于其较低电导率与储钾过程中巨大体积变化。与碳材料的结合虽能改善其导电性与结构稳定性，但磷/碳负极材料仍面临严重结构坍塌与剧烈界面副反应及迅速性能衰减等问题。在此，我们采用空隙结构设计与复合界面重构协同增强磷/碳负极结构与界面稳定性。首先，以碳酸钙/磷自氧化层/氧化铝为模板将空隙结构引入磷/碳负极材料中，提升其结构稳定性与电化学可逆性。其次，采用分子/原子层沉积技术在磷/空隙/碳负极材料表面可控构筑无机复合物（Al2O3或TiO2/C）、钾离子无机固态电解质（KMxOy，M=Al或Ti）和有机/无机复合物（Alucone或Titanicone/KMxOy）包覆层，抑制其在电解液中的界面副反应，维持其结构完整性与电化学活性。先进表征手段对储钾机制的研究也将为开发钾离子电池高性能磷基负极打下坚实基础。

As a naturally abundant and inexpensive material, phosphorus can alloy with several potassium ions, leading to a high theoretical capacity and an outstanding energy density. Unfortunately, the potassium storage capability of phosphorus anode has chronically been diminished by its intrinsically low electrical conductivity and a huge volume change upon potassiation/depotassiation. Even though its combination with carbon materials could ameliorate the poor electrical conductivity and further improve the structural stability, the phosphorus/carbon anode materials are still suffered from a severe structural collapse, a violent interfacial side reaction, and a rapid capacity degradation upon cycling. In this project, we have incorporated void structure designs with hybrid interface designs for synergistically enhancing structural/interfacial stabilities of phosphorus/carbon anode materials. Initially, we would take advantages of calcium carbonate/phosphorus self-oxidation layer/aluminum oxide as templates to create void structures in phosphorus/carbon anode materials for promoting their structural stability and electrochemical reversibility. Additionally, we would further utilize molecular/atomic layer deposition to rationally construct inorganic composites (Al2O3 or TiO2/C), potassium-ion inorganic solid electrolytes (KMxOy, M=Al or Ti), and organic/inorganic composites (Alucone or Titanicone/KMxOy) as coatings on the surface of phosphorus/void/carbon anode materials. Intriguingly, these hybrid interlayer reconstructions are supposed to suppress the parasitic reactions of phosphorus/void/carbon anode materials with volatile electrolytes and maintain their structural integrity/electrochemical activity. Simultaneously, the potassium storage mechanisms would be further clarified by advanced characterization techniques to lay the solid foundations of developing high-performance phosphorus-based anodes for potassium-ion batteries.