Stringing them along: The pores of a mesoporous silica particle were filled with guest molecules and then blocked by threading cyclodextrin molecules (CDs) onto the surface‐grafted polyethylenimine (PEI) chains at pH 11. At pH 5.5, the guest molecules can be released from the pores of the particle by reversible dethreading of the CDs from the PEI chains.

Aufgefädelt: Die Poren eines mesoporösen Siliciumoxidpartikels wurden mit Gastmolekülen gefüllt und anschließend durch das Auffädeln von Cyclodextrinmolekülen (CDs) bei pH 11 auf an der Oberfläche fixierte Polyethylenimin(PEI)‐Ketten blockiert. Bei pH 5.5 wurden die Gastmoleküle aus den Partikelporen durch reversibles Abfädeln der CDs von der PEI‐Kette freigesetzt.

Electrolyte additives, as a small proportion of the electrolyte, greatly affect the performance of lithium-ion cells. This work performs a comparative study to reveal the difference between commercial 99.8% pure 3-phenyl-1,4,2-dioxazol-5-one (PDO) additive and lab-made 95% pure PDO in NMC622/graphite cells. In addition, a set of experiments were conducted to evaluate the performance of 99.8% pure PDO and its binary blends with vinylene carbonate (VC), 1,3,2-dioxathiolane-2,2-dioxide (DTD) or lithium difluorophosphate (LFO) in NMC811/graphite cells. 99.8% Pure PDO and 95% pure PDO show little difference in the NMC622 cells, with the latter presenting relatively better performance in the best-performing blends for long-term cycling and high-temperature storage tests. Considering all the tests including ultra high precision coulometry (UHPC) cycling, long-term cycling, and high-temperature storage, the NMC811 cells with 2%PDO+1%LFO outperformed the other PDO-containing cells. The PDO-based blends were confirmed to be more promising in cells with higher nickel content; that is, PDO could be a useful additive in high-nickel content cells.