Polytriphenylamine derivative with high free radical density as the novel organic cathode for lithium ion batteries

Abstract

Polytriphenylamine derivative, poly[N,N,N,N-tetraphenylphenylenediamine] (PDDP), with a high free radical density, has been synthesized and studied as a cathode material for organic free radical batteries for the first time. The chemical structure, morphology, and electrochemical properties of the prepared polymers were characterized by Raman spectra (RS), electron spin resonance (ESR), ultraviolet visible spectroscopy (UVVis), scanning electron microscopy (SEM), cyclic voltammograms (CV), and electrochemical impedance spectra (EIS), respectively. In addition, the charge-discharge properties of the prepared polymers were studied by galvanostatic charge-discharge testing. Compared to polytriphenylamine (PTPA), the fabricated lithium ion half-cells based on PDDP as the cathode exhibited two well-defined plateaus at two discharge voltages of 3.8 and 3.3 V vs. Li/Li + and an improved capacity of 129.1 mA h g À1 , which was very close to its theoretical capacity (130 mA h g À1 ). The excellent electrochemical performances of the PDDP electrode were due to its stable chemical structure and high free radical density, which makes the PDDP a promising free radical cathode material for organic lithium secondary batteries.

The rise of organic electrode materials for energy storage

“…A polytriphenylamine derivative 135 was reported as a cathode material for dual-ion batteries, using lithium as the anode, that had a better performance than polytriphenyl amine itself. 139 Due to the higher radical density and C theor than polytriphenyl amine, 135 achieves a much higher C sp (129.1 mA h g À1 at 20 mA g À1 and 92.8 mA h g À1 at 500 mA g À1 ). This material has two voltage plateaus at 3.8 V and 3.3 V vs. Li/Li + and an 85.6% capacity retention after 50 cycles at 20 mA g À1 .…”

Polymer Electrode Materials for High‐Performance Lithium/Sodium‐Ion Batteries: A Review

“…Su et al synthesized poly[ N , N , N , N ‐tetraphenylphenylenediamine] (PDDP) with a high free radical density . The increased number of radicals per unit contributed to a high specific capacity for PDDP as a cathode material in LIBs.…”

“…a) SEM images of PTPA and b) PDDP powder samples; cycling performance of c) PDDP and d) PFTP electrodes at a constant current of 20 mA g −1 within the voltage range of 2.5–4.2 V; e) the synthesis route of PFTP; a–c) Reproduced with permission . Copyright 2013, The Royal Society of Chemistry.…”

Triphenylamine and some of its derivatives as versatile building blocks for organic electronic applications

“…Applications include various thin layer opto‐electronic devices comprising organic light emitting diodes (OLEDs), electrochromic devices, dye sensitized solar cells, organic solar cells (OSCs) and perovskite solar cells . The electron‐rich character of TPA has also been exploited for electrochemical storage of energy and electrical memory devices . The use of TPA derivatives is particularly appealing due to a number of desirable properties, including their synthetic accessibility and the possibility of finely tuning their redox and absorption characteristics.…”