Triblock Copolymer/Polyoxometalate Nanocomposite Electrolytes with Inverse Hexagonal Cylindrical Nanostructures

Abstract

The primary issue of polymer electrolytes is to achieve high ion conductivity while retaining mechanical properties. A nanocomposite electrolyte with the inverse hexagonal cylindrical phase (three‐dimensionally continuous domains for ion conduction and embedded domains for mechanical support) is prepared through the electrostatic self‐assembly of a polyoxometalate (H3PW12O40, PW) and a triblock copolymer poly(N‐vinyl pyrrolidone)‐block‐polystyrene‐block‐poly(N‐vinyl pyrrolidone) (PSP). The cylindrical nanocomposite exhibits a conductivity of 1.32 mS cm−1 and a storage modulus of 4.6 × 107 Pa at room temperature. These two values are higher than those of pristine PSP by two orders of magnitudes and a factor of six, respectively. PW clusters are used as multifunctional nano‐additives (morphological inducer, proton conductor, and nano‐enhancer) and their incorporation achieves the simultaneous improvement in both conductive and mechanical performance.

Nanostructured Polymer Composite Electrolytes with Self-Assembled Polyoxometalate Networks for Proton Conduction

“…We found that the conductivities of PGP8-30, PGP17-23, and PGP23-30 at 353 K are increased from 7.6, 18.2 to 32.7 mS cm −1 , accompanied by a decreased activation energy from 0.16, 0.13 to 0.12 eV by Arrhenius fitting (Figure 5c and Table 1), respectively, which corresponds to a Grotthuss-type proton conduction mechanism. 60 The contents of PW in PGP8-30, PGP17-23, and PGP23-30 are all 30 wt % and thus lead to the same IEC of 0.31 mmol g −1 . Given this situation, the enhanced conductivities and the decreased E a from PGP8-30, PGP17-23 to PGP23-30 should be ascribed to the improved connectivity of PW networks but not the IEC.…”

“…[48][49][50] Recently, the excellent proton conductivity, electrochemical stability, and water-retention ability of POMs have attracted special interest to develop POM-polymer composite electrolytes for proton conduction. [51][52][53][54][55][56][57][58][59][60][61] However, it is difficult to manipulate the distribution of POMs in polymer electrolytes to form well-connected proton conductive pathways, as the strong electrostatic interaction easily induces the disordered aggregation of POMs. Recently, Guiver and co-workers reported a breakthrough they obtained: one-dimensional (1D) POM-based protonconducting channels in a homopolymer electrolyte matrix through an external magnetic field alignment.…”

Polyoxometalates as chemically and structurally versatile components in self-assembled materials

“…Unfortunately, the hybrid material was unstable in high ionic strength media due to the weakened electrostatic interactions between the POM and polymer, which limited the application of these compounds in the field of bio-imaging and bio-detection. 15 as electrostatic crosslinkers to form bicontinuous 41 inverse hexagonal 42 and lamellar morphologies 43 with the positively charged polymer poly(styrene-b-2-vinylpyridinium) (PS-b-P2VP). These nanocomposites exhibited enhanced proton conductivity and mechanical strength as the result of using macroions as functional additives.…”

“…The extent of polymerisation was shown to impact the POM sensitized emission. 40 The group of Haolong Li used [PW 12 O 40 ] 3À and [SiW 12 O 40 ] 4À (P3) as electrostatic crosslinkers to form bicontinuous 41 inverse hexagonal 42 and lamellar morphologies 43 with the positively charged polymer poly(styrene-b-2-vinylpyridinium) (PS-b-P2VP).…”

“…The group of Haolong Li used [PW 12 O 40 ] 3− and [SiW 12 O 40 ] 4− (P3) as electrostatic crosslinkers to form bicontinuous 41 inverse hexagonal 42 and lamellar morphologies 43 with the positively charged polymer poly(styrene- b -2-vinylpyridinium) (PS- b -P2VP). These nanocomposites exhibited enhanced proton conductivity and mechanical strength as the result of using macroions as functional additives.…”