Improving the Performance of Batteries by Using Multi‐Pyrene PTMA Structures

Abstract

Well‐defined pyrene‐based poly(2,2,6,6‐tetramethylpiperidinyloxy‐4‐yl methacrylate) (PTMA) (co)polymers have been synthesized and combined with multi‐wall carbon nanotubes (CNTs) as electrode material for organic radical batteries. The influence of the number of pyrene pendent groups on the electrochemical response of the nanocomposite materials has been assessed, focusing on the capacity retention upon charge/discharge cycling and on the cycling rate. In parallel, the interactions between the polymethacrylate chains and the CNT surface have been investigated with molecular modeling techniques, to shed light on the nature and stability of the functionalized PTMA/CNT interface.

Ion-Conducting Redox-Active Polymer Gels Based on Stable Nitroxide Radicals

“…The network was swollen in DCM to form a gel, was filtered on 0.5 µm PTFE filter and dried in vacuum at 40 °C. Once the PTMPM network was dried, it was oxidized into a PTMA network, following a previously described procedure [15]. More precisely, a round-bottomed flask equipped with a condenser was filled with PTMPM network (2.32 g, 10.3 mmol of amine functions, 1 eq.…”

“…Moreover, the corresponding electrodes are characterized by a typical capacity fading upon cycling, due to continuous leaking of PTMA into the liquid electrolyte. In order to overcome the solubility problem of PTMA into the electrolyte, several strategies have been explored over the last years, including increasing the molar mass of PTMA [11], cross-linking PTMA chains into a network [12], and by physically or chemically grafting PTMA chains onto the conductive carbons [13,14,15]. Although those strategies have proven their usefulness, it is important to keep good solubility of the PTMA chains, in order to allow good accessibility for the lithium salts to the nitroxide radicals, and to exploit the full potential of the ultra-fast redox reactions of the nitroxide groups.…”

100th Anniversary of Macromolecular Science Viewpoint: Fundamentals for the Future of Macromolecular Nitroxide Radicals

“…5,37,65 Besides RAFT polymerization, ATRP has also been demonstrated for the indirect production of PTMA, resulting in M n ≤ 24 700 g/mol and Đ ≤ 1.2. 5,32,67 Finally, single electron transfer-living radical polymerization produced PTMA with M n ≤ 131 000 g/mol and Đ ≤ 1.3, which resulted in the highest molar mass PTMA found in the literature. 68,69 Although most work has focused on controlled polymerization methods, other indirect methods such as free radical polymerization (FRP), 2,4,8,29,35,70 group transfer polymerization, 71,72 and cationic polymerization 73 have also been investigated to produce nitroxide-containing polymers, but these methods typically result in similar M n values (36 000− 130 000 g/mol) with larger dispersity (1.4−3.5).…”

“…Another approach to high radical loading is to indirectly synthesize the macromolecular nitroxide radical by polymerization of the precursor monomer, followed by oxidation or deprotection to generate the nitroxide radical. One example of this indirect synthesis is the RAFT polymerization of PTMA or PTMA copolymer using a dithiobenzoate or trithiocarbonate RAFT agent. ,, The resulting polymers had M n ≤ 24 000 g/mol and Đ ≤ 1.3. ,, Besides RAFT polymerization, ATRP has also been demonstrated for the indirect production of PTMA, resulting in M n ≤ 24 700 g/mol and Đ ≤ 1.2. ,, Finally, single electron transfer-living radical polymerization produced PTMA with M n ≤ 131 000 g/mol and Đ ≤ 1.3, which resulted in the highest molar mass PTMA found in the literature. , …”

Phosphaviologen‐Based Pyrene‐Carbon Nanotube Composites for Stable Battery Electrodes

“…In addition, the aromatic nitrogen atoms can be used as a synthetic handle to attach functional groups via quaternization, imparting specific material properties. We take advantage of this by coupling pyrene pendants to the phosphaviologen core allowing the small molecule to physisorb to single‐walled carbon nanotubes (SWCNTs), which is expected to prevent electrode dissolution . As a result, these electrodes have high voltages relative to Li/Li + and possess high cycle stability.…”