The development of new batteries has historically been achieved through discovery and development cycles based on the intuition of the researcher, followed by experimental trial and error—often helped along by serendipitous breakthroughs. Meanwhile, it is evident that new strategies are needed to master the ever‐growing complexity in the development of battery systems, and to fast‐track the transfer of findings from the laboratory into commercially viable products. This review gives an overview over the future needs and the current state‐of‐the art of five research pillars of the European Large‐Scale Research Initiative BATTERY 2030+, namely 1) Battery Interface Genome in combination with a Materials Acceleration Platform (BIG‐MAP), progress toward the development of 2) self‐healing battery materials, and methods for operando, 3) sensing to monitor battery health. These subjects are complemented by an overview over current and up‐coming strategies to optimize 4) manufacturability of batteries and efforts toward development of a circular battery economy through implementation of 5) recyclability aspects in the design of the battery.

Head-to-tail regioregular poly­(4-alkylthiazole)­s containing silylethers in the side-chains were synthesized via Kumada-Coupling polycondensation of “reversed” monomers, that were metalated at the sterically hindered 5-position. Their optical, electrochemical, and bulk properties have been studied, and evidence is presented that indicates the occurrence of quasi-living chain-growth behavior in the polymerization process. Two polymers, PTzTIP and PTzDIBO, featuring triisopropylsilyl and diisobutyloctadecylsilyl side chains, respectively, were prepared. PTzTIP is largely insoluble, while PTzDIBO is fully soluble in common organic solvents, including hexane, and readily gave number-averaged molecular weights exceeding 100 kDa, corresponding to an average degree of polymerization greater than 200, as determined via gel-permeation chromatography (GPC) in CHCl3. The formation of a regular head-to-tail regiostructure could be confirmed through comparison with a head-to-head–tail-to-tail regioregular polybithiazole (PBTzTIP), synthesized via Yamamoto-polymerization of a head-to-head-linked bithiazole. Regioregular PTzDIBO could be obtained via different polymerization protocols, including external initiation with two new aryl-nickel-complexes, which furnished material with particularly low polydispersities (<1.4 at M n > 100 kDa). Furthermore, a direct correlation between the obtained molecular weight and the monomer/catalyst ratio was observed in series of batch polymerization experiments, in agreement with a chain-growth polycondensation process. The incorporation of the precatalyst–aryl moiety into the polymer chains could be proven by comparison with a model compound. The functionalized end-groups allowed to independently determine the molecular weight via 1H NMR, which gave good agreement with the values obtained from GPC, further corroborating the occurrence of chain-growth.

Head-to-tail regioregular poly(4-alkylthiazoles) (C 9 -pTz, C 13 -pTz, alkyl = n-C9H19, n-C13H27) have been synthesized and spectroscopically and electrochemically characterized. The PTzs were obtained by transmetalation of 2-chloro-5-bromo-4-alkylthiazoles with i PrMgCl, followed by Kumada-coupling polycondensation. The polymers are largely insoluble in organic solvents but dissolve readily in the presence of, e.g., trifluoro acetic acid (TFA). Analyses of soluble trace fractions of the polymers gave number average molecular weights (M n) of 1.9–2.4 kDa (C 9 -pTz, PDI ≈ 1.1–1.3) and 2.9–3.0 kDa (C 13 -pTz, PDI ≈ 1.1–1.2), as determined by gel permeation chromatography (GPC) relative to polystyrene standards, while the molecular weight of the bulk material is presumed to be considerably higher. Comparison of the 1H NMR spectra of the PTzs with a quaterthiazole model compound (4Tz) and head-to-head–tail-to-tail regioregular polybithiazole (PBTz) confirmed the head–tail structure and the high degree of regioregularity. The optical and electrochemical band gaps of C 9 -PTz were found to be similar to those of poly(3-hexylthiophene) (P3HT), while the frontier orbital levels are stabilized by 0.3–0.5 eV relative to those of the polythiophene. The synthesis of PTz via selective transmetalation of the precursor at the sterically hindered 5-position renders this synthesis a rare polycondensation of a reversed monomer. The implications for the polymerization mechanism are also discussed.

In this report we demonstrate that labile intramolecular N→B-Lewis pair formation can serve to tailor the properties of π-conjugated electronic materials.

We describe the preparation of arylisocyanide monomers bearing conjugated fulvenyl groups derived from 9-benzylidene-9H-fluorene (Flu), 5-benzylidene-1,2,3,4-tetraphenyl­cyclopentadiene (TPCp), and 5-benzylidene-5H-dibenzo­[a,d]­cycloheptene (Dbs). The electrochemical and optical properties of the monomers and their precursors have been characterized and consistently showed the effect of the conjugation of the respective functional group (−NO2, −NH2, −NHCHO, and −NC) with the fulvenyl moiety. The isocyanides have been subsequently polymerized to the corresponding polyisocyanides (PICs), which exhibited number-average molecular weights of 124–136 kDa (PDI = 2.0–2.7), as determined by gel permeation chromatography in THF vs polystyrene standards. The thermal, optical, and electrochemical properties of the polymers have been studied in detail. Spectroelectrochemical analyses of polymers equipped with redox-active pentafulvene groups show reversible electrochromism, which allows to lower the optical gap from 2.38 to 1.20 eV (Flu) and from 2.27 to 1.55 eV (TPCp) via chemical or electrochemical reduction.