The Role of Conductive Polymers in Alkali‐Metal Secondary Electrodes

Abstract

The electrochemical characteristics of electrodes composed of composites of conducting polymers and alkali‐metal alloys have been investigated. We have found that the addition of poly(p‐phenylene) (PPP) to alkali‐metal alloys greatly enhances the cyclability and the rate capability of alkali‐metal alloys. The impedance of these electrodes has also been studied. The composite electrode combines the capacitive behavior of PPP with the diffusion‐limited behavior of a pure alloy electrode. The conducting polymer component in a composite electrode acts to mediate the transfer of ions between the electrolyte and the alloy.

Non-aqueous electrolytes for sodium-ion batteries

“…20 and 21) as positive electrode materials using either liquid or polymer electrolytes, and some rst attempts to build Na-ion cells with Na 15 Pb 3 negative electrodes (as opposed to using Na metal) were also reported. 22,23 Unfortunately, this research path was largely abandoned due to the advent of the LIB technology for portable electronics and its prospects of a much more generalized eld of application. There was one remarkable exception: the patent of a full SIB by Valence Technologies (US) in 2002, 24,25 consisting of a carbonaceous negative electrode coupled to a sodium transition metal phosphate positive electrode using 1 M NaClO 4 in EC : DMC (2 : 1) as an electrolyte.…”

Tin–Germanium Alloys as Anode Materials for Sodium-Ion Batteries

“…15 Experimental data are available for germanium, 33,34 tin, 35−38 and lead. 39 Sodium alloys with Sn up to a thermodynamic limit of Na 15 Sn 4 provide a theoretical capacity of 847 mAh g −1 , making it an attractive candidate. However, the capacity is not well retained on cycling, with particle aggregation and electrode/electrolyte instability being cited as causes of degradation.…”

Direct atomic-scale confirmation of three-phase storage mechanism in Li4Ti5O12 anodes for room-temperature sodium-ion batteries

“…In contrast, very few anode materials were reported to be viable 5,20 . Among the limited number of anode materials 13,[21][22][23][24][25][26][27][28][29] , hard carbon is the only candidate possessing both high storage capacity and good cycling 13,23 . However, as the sodium storage voltage in hard carbon is relatively low and near zero versus Na þ /Na, this would result in sodium metal deposition on its surface in an improper operation or during fast charging, giving rise to major safety concern.…”