Lignocellulose flow fuel cells are promising technologies for large scale generation of renewable electricity at low temperature. However, most of them have low electron transfer kinetics and require pre-reaction and redox mediators in anolytes for a liquid-phase catalytic reaction, which leads to low power density, energy consumption and resource waste. Herein, we develop a new low temperature and high-power density lignin flow fuel cell (LFFC) catalyzed by CoMn-LDH electrocatalysts with superhydrophilic intercalation on the anode to efficiently degrade lignin and transfer electrons rapidly. The experiments and DFT calculations show that CoMn-LDH exhibits high adsorption capacity for lignin due to its superhydrophilic intercalation, and has good electrical conductivity due to the greater overlap of antibonding orbitals and high continuity at the Fermi level. Moreover, the abundant oxygen defects of CoMn-LDH can depolymerize lignin effectively. Thus, the prepared CoMn-LDH electrocatalyst enables fast charge transfer and high catalytic efficiency. The power density of the designed LFFC reached 269.3 mW cm⁻², and the generated electrical energy is 294.7 mW h based on 1.0 g of lignin, which are obviously higher than those of the reported LFFCs. Furthermore, it can work stably for more than 9 h at 0.3 V and 413.5 mA cm⁻², and successfully power a 1.5 V LED pattern with only a 1 cm² active membrane. It presents a promising approach for developing high-power density LFFCs towards a sustainable society.

中文翻译：

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采用具有超亲水插层的高效 CoMn-LDH 电催化剂的低温高功率密度木质素流燃料电池

木质纤维素流动燃料电池是在低温下大规模生产可再生电力的有前途的技术。然而，它们大多数具有较低的电子转移动力学，并且需要阳极液中的预反应和氧化还原介体来进行液相催化反应，这导致功率密度低、能源消耗和资源浪费。在此，我们开发了一种新型低温高功率密度木质素流燃料电池（LFFC），由阳极上超亲水插层的CoMn-LDH电催化剂催化，可有效降解木质素并快速转移电子。实验和DFT计算表明，CoMn-LDH由于其超亲水插层而对木质素表现出高吸附能力，并且由于反键轨道重叠更大和费米能级的高连续性而具有良好的导电性。此外，CoMn-LDH丰富的氧缺陷可以有效地解聚木质素。因此，所制备的CoMn-LDH电催化剂能够实现快速电荷转移和高催化效率。所设计的LFFC的功率密度达到269.3 mW cm ^-2，基于1.0 g木质素产生的电能为294.7 mW h，明显高于报道的LFFC。此外，它可以在0.3 V和413.5 mA cm ^-2下稳定工作超过9小时，并成功地仅用1 cm ²活性膜为1.5 V LED图案供电。它为开发高功率密度LFFC以实现可持续社会提供了一种有前景的方法。