Biomass flow fuel cells (BFFCs) are promising alternatives for large-scale conversion of biomass into electricity at low temperature. However, most of them are based on single redox-active materials in anolyte which have limited capacity density and electron transfer rate, resulting in many natural biomass residues can’t generate electricity rapidly and efficiently. Herein, we develop a new anodic electron transfer chain based on CuCl₂/TiOSO₄ synergetic mediators for BFFCs. The density functional theory (DFT) simulation and experiment results show that TiO²⁺/Ti³⁺ redox couple works as an intermediate medium to construct a CuCl₂/TiOSO₄ synergetic electron transfer chain, which strengthens the electron transfer rate between anolyte and graphite felt (GF) electrode. The CuCl₂/TiOSO₄ synergetic mediators can efficiently and rapidly degrade glucose, industrial lignin and other natural biomasses at low temperature, and extract electrons simultaneously for generating electricity. The maximum power density (P_max) of CuCl₂/TiOSO₄-based BFFC is 146.7 Mw·cm^-2 when the anolyte is pre-reacted at 90 ℃ for 1h with glucose as fuel and paired with VO₂⁺/VO²⁺ catholyte. And the fuel cell can discharge electricity continuously and stably for more than 6 hours at 400 mA·cm^-2. Furthermore, it can stably power LED pattern with 92 bulbs. Besides, when the CuCl₂/TiOSO₄-based BFFC utilizes sodium lignosulfonate as fuel, its P_max is 55.1 mW·cm^-2, and the BFFC can discharge electricity stably for more than 1 h at high output current density of 1.3 A·cm^-2. This work provides a promising approach for application in direct biomass wastes power generation.

生物质流燃料电池（BFFC）是在低温下将生物质大规模转化为电能的有前途的替代品。然而，它们大多基于阳极液中的单一氧化还原活性材料，容量密度和电子转移率有限，导致许多天然生物质残渣不能快速高效地发电。在此，我们开发了一种基于 CuCl ₂ / TiOSO ₄协同介质的新型阳极电子转移链，用于 BFFC。密度泛函理论(DFT)模拟和实验结果表明，TiO ²⁺ /Ti ³⁺氧化还原对作为中间介质构建CuCl ₂ /TiOSO ₄协同电子传递链，增强阳极液和石墨毡 (GF) 电极之间的电子传递速率。CuCl ₂ /TiOSO ₄协同介质可以在低温下高效快速地降解葡萄糖、工业木质素等天然生物质，同时提取电子进行发电。CuCl ₂ / TiOSO ₄基BFFC的最大功率密度（P _{max ）为146.7 Mw·cm} ^-2阳极液以葡萄糖为燃料在90 ℃下预反应1h并与VO ₂ ⁺ /VO ^2+配对阴极液。^{该燃料电池在400 mA·cm -2}下可连续稳定放电6小时以上。此外，它可以稳定地为 92 个灯泡的 LED 图案供电。此外，CuCl ₂ / TiOSO ₄基BFFC以木质素磺酸钠为燃料时，其P _max为55.1 mW·cm ^-2，在1.3 A·高输出电流密度下，BFFC可稳定放电1小时以上。厘米^-2。这项工作为直接生物质废物发电的应用提供了一种有前景的方法。