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[Display omitted] • A concept of multifunctional Li+ traffic controller is proposed. • The traffic controller can effectively regulate the distribution of Li+. • The traffic controller stabilizes the electrode-electrolyte interface. • The traffic controller layer enables ultra-low N/P ratio full cells. The performance of thin lithium metal anodes is affected due to issues that weaken the electrode-electrolyte interphase. In this work, a coating layer serving as a Li+ traffic controller based on hexadecyl trimethyl ammonium bis(trifluoromethanesulphonyl)imide ([CTA][TFSI]) and poly (vinylidene difluoride co-hexafluoropropylene) (P(VDF-HFP)) is used to stabilize the thin lithium metal interface. The CTA+ ions in the coating layer can effectively regulate the distribution of Li+ concentration to promote uniform deposition of lithium. The anion of [CTA][TFSI] can optimize solid electrolyte interphase (SEI) with inorganic-rich components, which improve the ionic conductivity and reaction kinetics. Furthermore, the flexible polymer skeleton can fortify the fragile SEI, facilitating the consistent operation of the battery. Due to these improvements, a thin Li metal anode (4 mAh cm−2) with a coating layer in a Li||Li symmetric cell demonstrates a lifespan of 600 h at 1 mA cm−2 and 1 mAh cm−2. Notably, full cells with an ultra-low negative electrode/positive electrode = 1 (N/P = 1) demonstrate a stable performance over 200 cycles and 90 cycles at 0.5C and 1C (1C = 170 mA g−1), respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] Solid-state polymer electrolytes are outstanding candidates for next-generation lithium metal batteries in the realm of high specific energy densities, high safeties and tight contact with electrodes. However, their applications are still hindered by the limitations that no single polymer is electrochemically stable with the oxidizing high-voltage cathode and the highly reductive Li anode, simultaneously. Herein, a bilayer asymmetric polymer electrolyte (SL-SPE) without accessional interface resistance that using poly (ethylene glycol) diacrylate (PEGDA) as a "bridge" to connect the sulfonyl (O S = O)-contained oxidation-tolerated layer and polyether-derived reduction-tolerated layer (SPE), is proposed and synthesized by sequential two-step UV polymerizations. SL-SPE can provide widened electrochemical stability window up to 5 V, while simultaneously deploying a stable Janus interface property. Eventually, the superior high-voltage (4.4 V) cycling durability can be displayed in LiNi 0.6 Co 0.2 Mn 0.2 O 2 |SL-SPE|Li batteries. This finding provides a bran-new idea for designing multifunctional polymer electrolytes in the application of solid-state batteries. [ABSTRACT FROM AUTHOR]

Stable and active Pt electrocatalyst preparation by a modified citrate reduction method and a mechanism analysis of inorganic additives. • Pt with a clean surface were synthesized via a modified citrate reduction method. • NO 2 − ions possibly alter the reaction kinetics of the growth of Pt NPs. • The optimized Pt/CNT demonstrated high mass activity and moderate activity decay. • The maximum power density of the optimized Pt/CNT catalysts at 0.6 V is 744 mW cm−2. Ultra-small and monodispersed Pt nanoparticles (NPs) have been successfully synthesized in polymer electrolyte membrane fuel cells. The process normally involves the use of capping agents, organic species, templates, and substrates and is thus complex. Hence, obtaining Pt NPs with a clean surface is challenging. In this study, a method for preparing stable and highly dispersed Pt NPs with clean surfaces is proposed. The method involves the use of a modified Na 3 C 6 H 5 O 7 reduction process assisted by NaNO 3 stabilization. The specific complexations of NO 2 − ions possibly alter the reaction kinetics and lower the growth rate of Pt NPs by retarding the reduction reaction. The optimized Pt/carbon nanotube (CNT) catalysts exhibit high mass activity and moderate activity decay after 10,000 times of potential cycling compared with commercially available Pt/C catalysts. Then, membrane electrode assemblies based on the resultant catalysts are characterized. The cell performance of 744 mW cm−2 (maximum power density) is achieved after the optimized Pt/CNT catalysts are used in carbon black. [ABSTRACT FROM AUTHOR]