Rechargeable Potassium–Selenium Batteries

Abstract

Rechargeable potassium-selenium (K-Se) batteries, as an emerging electrochemical energy storage system, has recently captured intensive attention due to the desirable natural abundance and low redox potential of elemental potassium as well as the relatively high electronic conductivity and impressive theoretical volumetric capacity of elemental selenium. Although great progress on cathode materials design and electrochemical performance improvement has been made, K-Se batteries are still confronted with a series of key challenges, including low reactive activity, shuttle effect, volume expansion, potassium dendrite growth, and high chemical activity of potassium metal. The recent advances in rechargeable K-Se batteries are comprehensively summarized with an emphasis on discussing the electrochemical mechanisms and central challenges, presenting the synthesis, properties, and electrochemical performance of selenium-based cathode materials, and extending potential tactics for tackling the key issues and developmental directions for future research.

Nano and Battery Anode: A Review

“…The Fig. 21 shows a comparison between the storage capacity of LTO capacity in three different Nano dimensions [ 78 ]. According to Fig.…”

“…This figure shows that in the first stage of lithium extraction, the anode behavior is significantly different from the next stage of charge and discharge. The hysteresis in this type of anode is up to one volt, while in the graphite and LTO anode it is about 0.2 V. This hysteresis is mostly due to activation polarization [ 78 , 79 ].

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“…The question may arise in the mind of the reader as to why other alloy anodes are being explored, given that silicon has a much higher capacity than other alloy anodes [71][72][73]. The answer that is given and can be generalized to the whole collection of nanotechnology and battery articles is that because nanomaterials are synthesized in different ways and with different morphologies (shapes) in different ways [74][75][76][77][78]. Each synthesis method is different from the discussion of price, quality, safety, scalability, environmental effects, etc.…”

“…20 Showing the atomic structure of the phase (TiO 2 (B) [77] Fig. 21 Demonstration of input and super capacitor capacities in titanium oxide [78] anode is up to one volt, while in the graphite and LTO anode it is about 0.2 V. This hysteresis is mostly due to activation polarization [78,79].…”

“…26 Display of SEM images, charge-discharge curves and cycle life for Nano-iron oxide and bulk [80] mechanism for iron oxide due to thermodynamic problems. The opposite happens for the Co 3 O 4 anode because it is kinetic and is related to the current density (the current density is obtained by dividing the current by the surface); when the current is constant, in the Nanodimensions, because the surface is higher, the current density decreases and the Co 3 O 4 anode shows exchange behavior, but in the micro, due to the high current density, the anode shows the insertion behavior [76][77][78][79].…”