New chemistry in making the nonflammable graphene oxide membranes for rechargeable batteries and fuel-cells
by Turgut, Hulusi; Rogers, Rachel; White, Cale; Tian, Z. Ryan
Graphene oxide (GO) has attracted broad interest in its great promise in large-scale prodn. of graphene-enabled energy harvesting and conversion devices such as rechargeable battery and proton-exchange membrane fuel-cell. However, GO's high flammability may bring a great deal of fire hazard to manufacturers and consumers of these devices. In our lab, residue potassium- and sulfur-contg. impurities in GO were found to be responsible to the GO's flammability, which has been seldom discussed in literature to date. In particular, a spark can cause disastrous combustion for the GO, and removing the impurities using filtration can be tedious, labor-intensive and time-consuming. Here we report a unique approach to making the new type of nonflammable GOs at ultralow-cost via a simple, one-step chem. reaction at ambient temp. and pressure, which substantially eliminates the impurities and in turn the fire hazard. Moreover, the chem. modification boosted the GO-membrane's elec. resistance up to 200M%Ï?/sq, which can largely broaden the new GO-membrane's applicability beyond the above-mentioned important applications.