Engineering the interface of organic/inorganic composite solid-state electrolyte by amino effect for all-solid-state lithium batteries.

Composite solid-state electrolyte (CSSE) with integrated strengths avoids the weaknesses of organic and inorganic electrolytes, and thus become a better choice for all-solid-state lithium battery (ASSLB). However, the poor dispersion of inorganic fillers and the organic/inorganic nature difference leads to their interface incompatibility, which greatly destroys the performance of CSSE and ASSLB. Herein, silane coupling agent (SCA) aminopropyl triethoxysilane (ATS) is introduced to tailor the organic/inorganic interfaces in CSSE by the common chemical bridging effect of SCA and the special amino effect (hydrogen bond and lone pair electron effects). It is found that the hydrogen bond interaction between -NH2 and polyethylene oxide (PEO) enhances their interface interaction. And the lone pair electrons on nitrogen atom allow it to react with solvent acetonitrile and promote the uniform dispersion of ceramic fillers. Moreover, the lone pair electrons can complex with Li+, which promotes the dissociation of Li salts, uniforms Li+ diffusion and inhibits the Li dendrite. Thanks to the above merits, the interface compatibility and stability of organic/inorganic CSSE are much enhanced by innovatively introducing ATS, showing high ionic conductivity and superior mechanical/thermal stability. The ASSLB with this modified CSSE exhibits excellent electrochemical performance with a reversible capacity of 140.9 mAh g-1 and a capacity retention of 94.4% after 280 cycles. These achievements offer a new insight into improving the stability of organic/inorganic CSSE interface and promoting their applicability into ASSLB.

Metal-Organic-Framework-Based Gel Polymer Electrolyte with Immobilized Anions To Stabilize a Lithium Anode for a Quasi-Solid-State Lithium-Sulfur Battery.

A lithium-sulfur (Li-S) battery is widely regarded as one of the most promising technologies for energy storage because of its high theoretical energy density and cost advantage. However, the shuttling of soluble polysulfides between the cathode and the anode and the consequent lithium anode degradation strongly limit the safety and electrochemical performance in the Li-S battery. Herein, a metal-organic-framework (MOF)-modified gel polymer electrolyte (GPE) is employed in a Li-S battery in order to stablize the lithium anode. In view of the abundant pores in the MOF skeleton, the as-prepared GPE not only immobilizes the large-size polysulfide anions but also cages electrolyte anions into the pores, thus facilitating a uniform flux of Li ions and homogeneous Li deposition. Cooperated with a sulfur-carbon composite cathode, the lithium with MOF-modified GPE exhibits a uniform surface morphology and dense solid electrolyte interphase (SEI) film, thus delivering good cycle stability and high-rate capability.