Ultrathin-graphite foam with high mechanical resilience and electroconductibility fabricated through morphology-controlled solid-state pyrolysis of polyaniline foam

Three-dimensional carbon-based foam (3D-CF) possesses many fascinating properties such as giant conductivity, high thermal insulation , outstanding mechanical performance, and excellent chemical and thermal stabilities. However, most 3D-CFs acquired by the previously reported fabrication methods have some limitations, such as uncontrollable morphology, plenty of inherent defects, difficult to realize self-standing after removing sacrificial template, and overlapping joint flaws among graphene layers . Although significant research efforts have been devoted to develop 3D foam, it is still a challenging task to obtain 3D-CF with both high conductivity and outstanding mechanical performance, simultaneously. To address this issue, a novel and easy fabricating approach for 3D ultrathin-graphite carbon foam (3D-UGF) was explored by a morphology-retaining pyrolysis of polyaniline foam precursors. The typical 3D-UGF graphitized at 2800 °C exhibited stronger compressive strength and electrical conductivity under the compressive strain of 90%, and remained constant even after 2000 cycles, which are comparable to the previously reported state-of-the-art 3D-CF foam with the same density. Cycling performance of the lithium-sulfur and lithium-air batteries with the 3D-UGF as binder-free cathode is as high as 1590 mAh g −1 and 920 mAh g −1 after deep discharge/charge 100 cycles, respectively.