先进锂电池限域功能无机复合隔膜的制备及电化学性能研究

High-voltage lithium-ion batteries, lithium metal batteries and lithium-sulfur batteries are highly promising to be used in the energy storage fields due to their high energy densities. At present, the main limitations for these advanced lithium batteries are from their poor safety and disappointing lifetime. This project aims to design and prepare the inorganic composite separators with confinement function after surface modifications on the inorganic particles. The usage of inorganic composite separators with excellent thermal stability will significantly enhance the battery safety characteristics. Some electrolyte additives and soluble interface products will be confined in the area close to either the cathode or the anode via the interactions between the functional separator and the electrolyte compositions. Afterwards, the compositions and structures of the solid-electrolyte interfaces could be effectively adjusted and controlled in order to solve the "shuttle effect" in most battery systems. As the results, the stability of the state-of-the-art electrolytes at high potentials will be enhanced and lithium metal could be effectively protected by the suppression on lithium dendrites. By building various coating layers on the separators, the interactions between the separators and electrolyte compositions will be systemetacially investigated, and then the confinement mechanism of the inorganic composite separators toward the electrolyte additives and soluble interface products will be revealed. This project would potentially provide a solid theoretic and experimental foundation to promote the development of the inorganic composite separators with confinement function, and the advanced lithium batteries with high safety and long lifetime.

高电压锂离子电池、锂金属电池和锂硫电池具有高能量密度的优势，在储能领域有巨大的发展潜力，安全性差和循环寿命短是目前这些先进锂电池走向应用的主要障碍。本项目基于无机复合隔膜的制备与限域功能设计，利用无机复合隔膜优异的热稳定性显著提高电池安全性，通过无机粒子表面功能化将电解液功能添加剂或界面可溶物选择性限域在锂电池的正极侧或负极侧，高效调控电极与电解质界面组成与结构，解决电池普遍存在的“穿梭效应”，提高电解液的高电压稳定性与实现锂金属保护。通过构筑不同化学组成与组织形态的隔膜涂层，阐明隔膜表面官能团与电解液添加剂或界面可溶物间的相互作用，揭示无机复合隔膜对电解液添加剂与界面可溶物的限域机制，为推动无机复合隔膜的限域功能化发展与解决先进锂电池安全性与寿命问题提供重要的理论基础和实验依据。

先进锂电池（包括高电压锂离子电池、锂金属电池和锂硫电池）具有高能量密度的优势，在储能领域有巨大的发展潜力，安全性差和循环寿命短是目前这些先进锂电池走向应用的主要障碍。本项目通过限域功能设计，制备了勃姆石涂覆聚酰亚胺隔膜、Al2O3涂覆纤维素无纺布隔膜、rGO/MoO2涂覆聚丙烯隔膜、Sb2O3改性聚偏氟乙烯-三氟氯乙烯隔膜、碳纳米管-三维聚丙烯腈复合隔膜等多种具有限域功能的有机-无机复合隔膜，并对复合隔膜的结构、电化学性能和在电化学器件中的应用进行了系统地深入研究。利用无机复合隔膜优异的热稳定性显著提高了电池安全性，通过纳米氧化物无机粒子表面功能化将电解液功能添加剂或界面可溶物选择性限域在锂电池的正极侧或负极侧，高效调控电极与电解质界面组成与结构，有效解决了Li|LiNi0.5Mn1.5O4、Li|LiCoO2和锂硫电池普遍存在的“穿梭效应”，提高了电解液的高电压稳定性与实现锂枝晶的有效抑制。通过构筑不同化学组成与组织形态的隔膜涂层，阐明隔膜表面官能团与电解液添加剂或界面可溶物间的相互作用，揭示无机复合隔膜对电解液添加剂与界面可溶物的限域机制，为推动无机复合隔膜的限域功能化发展与解决先进锂电池安全性与寿命问题提供重要的理论基础和实验依据。