No abstract

Potassium-ion batteries have attracted substantial interest due to abundant resources and comparable electrochemical performance with lithium-ion batteries. Although plenty of graphene-based materials with ultrahigh performance have been designed, in practice, the dendrite growth induced by the capacitive-dominated potassium storage mechanism and the poor repeatability resulting from the complicated process are worrisome. To address these issues, it is envisaged that embedding SnCo nanoalloys in a graphene nanosheet matrix (SnCo NAs/G) can be an effective strategy for the following two reasons: (1) The embedded SnCo NAs are responsible for expanding the interlayer space and facilitating the potassium-ion diffusion in a graphene nanosheet matrix and (2) the combination of the microfluidic technology and the organic molecule confinement reaction endows the repeatability and large-scale production. As a result, the SnCo NAs/G-L anode is prepared with a low content of SnCo NAs (9.16 wt %). It shows advantages in the electrochemical performance as compared to the graphite anode. A reversible specific capacity of 165 mA h g–1 at 50 mA g–1 over 100 cycles is exhibited by SnCo NAs/G-L. It has a retention capacity of 179 mA h g–1, that is, 78.8% is recovered after charging at 500 mA g–1. Moreover, the intercalation reaction as the dominant potassium storage mechanism is beneficial for avoiding the safety problems arising from potassium dendrite growth. More interestingly, graphite-based composites constructed by the microfluidic technology successfully prove the high potential for large-scale production.

AIEgens have attracted intensive interest because of the unusual fluorescence feature. Although AIEgen-based materials have been developed for responding to the diverse ex-stimuli, such as mechano-, electro-, and thermal-stimuli, the practical application of AIEgen-based thermoluminescence is hampered for the following reasons: (1) high cost attributed to the complicated chemical modification, (2) low contrast and responsiveness resulting from the chromophoric property of the thermal functional group. In this contribution, a facile encapsulation technology-based strategy without any chemical modifications is developed to form the encapsulated TPE nanogels for the preparation of the AIEgen-based thermoluminescence. Thanks to the coexistence of the liquid and solid phases, the nanogel-based AIEgens can not only attain the transparent feature but also a reversible transformation between the single-molecule and aggregated state by ex-thermal stimuli. In the nanogel, the two aggregated states of TPE molecules are observed that result from being tangled by poly-TPGDA and from being self-assembled, respectively. Furthermore, the nanogels prepared at different temperatures demonstrate the controllable fluorescence intensity. The higher preparation temperature results in more aggregated TPE and higher fluorescence intensity. Finally, the nanogels are easily formed into the transparent film thermometers because of their flowability, which shows a switchable and stable fluorescence by ex-thermal stimuli. The transparent film thermometer demonstrates high potential in anticounterfeiting technology and biological imaging.