Zn metal has been considered as a promising anode material for rechargeable aqueous metal-ion batteries. However, the propensity of dendrite growth during plating restricts its practical applications. Herein we propose an effective, low-cost, and nontoxic electrolyte additive, tetrabutylammonium sulfate (TBA2SO4), as the first example of a cationic surfactant-type electrolyte additive in Zn-ion batteries, which can induce the uniform Zn deposition in both electrode preparation and the battery charge/discharge process. Electrochemical characterizations, in situ optical microscopy observation, along with density functional theory (DFT) calculations reveal the unique zincophobic repulsion mechanism, which results in the minimum addition amount of 0.029 g L–1 compared with other reported additives (at least 1g L–1), demonstrating the great potential for practical application. Excellent cycling performance with dendrite-free morphology at different current densities and discharge depths is achieved for both the symmetric cell and the full cell (coupled to α-MnO2) using the as-prepared 3D Zn anode and the proposed additives.

Abstract-The concept of 'Electric Spring (ES)' has beenproposed recently as an effective means of distributed voltage control. The idea is to regulate the voltage across the 'critical loads' while allowing the 'non-critical' impedance-type loads (e.g. water heaters) to vary their power consumption and thus contribute to demand-side response. In this paper a comparison is made between distributed voltage control using ES against the traditional single point control with STATCOM. For a given range of supply voltage variation, the total reactive capacity required for each option to produce the desired voltage regulation at the point of connection is compared. A simple case study with a single ES and STATCOM is presented first to show that the ES and STATCOM require comparable reactive power to achieve similar voltage regulation. Comparison between a STATCOM and ES is further substantiated through similar case studies on the IEEE 13-bus test feeder system and also on a part of the distribution network in Sha Lo Wan Bay, Hong Kong. In both cases, it turns out that a group of ESs achieves better total voltage regulation than STATCOM with less overall reactive power capacity. Dependence of the ES capability on proportion of critical and non-critical load is also shown.

No abstract

No abstract