Adjusting the solvation structure with tris(trimethylsilyl)borate additive to improve the performance of LNCM half cells

Tris(trimethylsilyl)borate(TMSB) has been intensively studied to improve the performances of lithiumion batteries. However, it is still an interesting issue needed to be resolved for the research on the Li^(+) solvation structure affected by TMSB additive. Herein, the electrochemical tests, quantum chemistry calculations, potential-resolved in-situ electrochemical impedance spectroscopy measurements and surface analyses were used to explore the effects of Li^(+) solvation structure with TMSB additive on the formation of the cathode electrolyte interface(CEI) film in LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)/Li half cells. The results reveal that the TMSB additive is easy to complex with Li^(+) ion, thus weaken the intermolecular force between Li^(+) ions and ethylene carbonate solvent, which is benefit for the cycle performance. Besides, the changed Li^(+) solvation structure results in a thin and dense CEI film containing compounds with Si–O and B–O bonds which is favorable to the transfer of Li^(+) ions. As a result, the performances of the LNCM811/Li half cells are effectively improved. This research provides a new idea to construct a high-performance CEI film by adjusting the Li^(+) solvation structures.

Gender difference in the effect of daytime sleep on declarative memory for pictures

Objective:To investigate gender difference in the effects of daytime sleep on item and source memories,which are dissociable elements of declarative memory,and the effects of sleep on recollection and familiarity,which are two processes underlying recognition. Methods:Participants saw a series of pictures with either blue or red background,and were then given a pretest for item and source memories. Then males and females respectively were randomly assigned either to a wake or a sleep condition. In the wake condition,participants remained awake until the posttest;in the sleep condition,participants slept for 1 h until awakened and asked to remain awake until the posttest. Results:Daytime sleep contributed to retention of source memory rather than item memory in females,whereas males undergoing daytime sleep had a trend towards increased familiarity. For females,however,neither recollection nor familiarity appeared to be influenced by daytime sleep. Conclusion:The mechanism underlying gender difference may be linked with different memory traces resulting from different encoding strategies,as well as with different electrophysiological changes during daytime sleep.