Polypyrrole Nanopipes as a Promising Cathode Material for Li‐ion Batteries and Li‐ion Capacitors: Two‐in‐One Approach

Abstract

Lithium ion capacitor (LIC) is a promising energy storage system that can simultaneously provide high energy with high rate (high power). Generally, LIC is fabricated using capacitive cathode (activated carbon, AC) and insertion‐type anode (graphite) with Li‐ion based organic electrolyte. However, the limited specific capacities of both anode and cathode materials limit the performance of LIC, in particular energy density. In this context, we have developed “two in one” synthetic approach to engineer both cathode and anode from single precursor for high performance LIC. Firstly, we have engineered a low cost 1D polypyrrole nanopipes (PPy‐NPipes), which was utilized as cathode material and delivered a maximum specific capacity of 126 mAh/g, far higher than that of conventional AC cathodes (35 mAh/g). Later, N doped carbon nanopipes (N‐CNPipes) was derived from direct carbonization of PPy‐NPipes and successfully applied as anode material in LIC. Thus, a full LIC was fabricated using both pseudo‐capacitive cathode (PPy‐NPipes) and anode (N‐CNPipes) materials, respectively. The cell delivered a remarkable specific energy of 107 Wh/kg with maximum specific power of 10 kW/kg and good capacity retention of 93 % over 2000 cycles. Thus, this work provide a new approach of utilization of nanostructured conducting polymers as a promising pseudocapacitive cathode for high performance energy storage systems.

Comparison of Charge Storage Properties of Prussian Blue Analogues Containing Cobalt and Copper

“…Representative examples of this analysis are shown in Figure S4, confirming that the charge storage kinetics for these samples is the result of mixed capacitive and diffusional behavior. Both an intermediate value of b in power-law fits and mixed kinetic behavior from Trasatti fits have been observed in a variety of intercalation charge storage systems [38][39][40][41][42][43][44][45][46]. The integrated charge capacity of the HCF films was calculated from 20 mV/s CV data.…”

Conjugated Molecules and Polymers in Secondary Batteries: A Perspective

“…Polypyrrole nanopipes have been proposed as positive electrode materials for lithiumion batteries [112]. They combine high-rate capability because of the established structure combined with improved storage capability in comparison to, e.g., activated carbon used for high-rate lithium-ion systems (batteries and capacitors) and mechanical stability.…”

Intrinsically conducting polymers and their combinations with redox-active molecules for rechargeable battery electrodes: an update

“…These additions (sometimes slightly misleadingly called dopants) frequently result in enhanced electronic conduction (for example, see (Zhang et al 2020b(Zhang et al , 2020d). Dubal et al (2019) have carbonized PPy-nanopipes yielding a host material for the negative electrode of a lithium-ion capacitor, together with the pristine nanopipes as positive electrode they assembled a capacitor keeping 93% of its initial capacitance after 2000 cycles. Whereas the positive electrode shows pseudocapacitive behavior (see Holze 2017), the negative electrode is a battery-type electrode.…”