Enhancement of the Electrode Activity of the Vanadium Redox Flow Battery by Higher Crystallinity of Carbon Matrix Using Seamless Porous-carbon Materials
Enhancement of the Electrode Activity of the Vanadium Redox Flow Battery by Higher Crystallinity of Carbon Matrix Using Seamless Porous-carbon Materials
复制标题
使用无缝多孔碳材料提高碳基结晶度提高钒氧化还原液流电池的电极活性
DOI：
10.1149/1945-7111/acaa5f
复制
发表时间：
2023
期刊：
影响因子：
--
通讯作者：
and Nobuyoshi Nakagawa
中科院分区：
文献类型：
--
作者：
2.H. Ishitobi;Honoka Doki;Soshi Shiraishi;Hidehiko Tsukada;Yoshikiyo Hatakeyama;Ryusuke Obata;and Nobuyoshi Nakagawa
钒氧化还原液流电池（VRFB）电极材料的碳基体的结晶度和表面氧基被认为对于增强电化学反应的活性非常重要。我们应用具有连续大孔的无缝碳材料作为 VRFB 的新型电极材料。我们将无缝碳材料在Ar气氛中从1200℃热处理到2200℃，然后在空气中在适当的温度下将它们氧化。尽管被认为是活性位点的表面氧基团的数量在碳基质的较高结晶度下减少，但在碳基质的较高结晶度下电极活性简单地增加。该结果表明，由于较高的 pKa 值，增加的 π 电子密度增强了活性材料与活性位点处的质子之间的离子交换。接下来，我们通过Ar气氛中的热分解研究了材料表面氧基团的必要性。表面氧基团热分解后电流密度显着降低。因此，表面氧基团被认为对于电化学反应至关重要。
The crystallinity of the carbon matrix and the surface oxygen groups of the electrode materials for vanadium redox flow batteries (VRFBs) are considered to be important for enhancing the activity of the electrochemical reactions. We applied seamless carbon materials with consecutive macropores as a novel electrode material for the VRFB. We heat-treated the seamless carbon materials from 1200 C to 2200 C in an Ar atmosphere, then oxidized them in air at the appropriate temperature. Although the number of surface oxygen groups, which are believed to be the active sites, decreased at the higher crystallinity of the carbon matrix, the electrode activity was simply increased at the higher crystallinity of the carbon matrix. This result suggests the increased π electron density enhanced the ion exchange between the active materials and protons at the active sites due to the higher pK a value. Next, we examined the necessity of the surface oxygen groups for the material by the thermal decomposition in the Ar atmosphere. The current density significantly decreased after the thermal decomposition of the surface oxygen groups. Hence, the surface oxygen groups are believed to be essential for the electrochemical reactions.