复旦大学彭慧胜团队设计了碳纳米管/氮化碳异质结构光电阴极实现高效稳定Li-CO₂电池。相关研究成果发表在2021年11月19日出版的《德国应用化学》。

Li-CO₂电池被认为是缓解环境问题和实现空间应用的有前途的动力系统。然而，缓慢的阴极CO₂还原/释放动力学导致所制备的储能器件的低往返效率和较差的循环稳定性。

该文中，研究人员设计了一种由碳纳米管和碳氮化物组成的异质结光电阴极，以加速Li-CO₂电池在光照下的阴极反应。得益于氮化碳独特的缺陷结构和良好的界面电荷转移，光电阴极高效地吸收紫外-可见光，生成丰富的光激发载流子，并协调高能光电子/空穴参与放电/充电反应，高效利用光能，降低反应势垒，提高Li-CO₂电池的热力学可逆性。由此产生的电池提供98.8%的高往返效率（0.04 V的超低电压滞后）和优异的循环稳定性（100次循环后效率保持率为86.1%）。

附：英文原文

Title: High-Efficiency and Stable Li-CO2 Battery Enabled by Carbon Nanotube/Carbon Nitride Heterostructured Photocathode

Author: Jiaxin Li, Kun Zhang, Yang Zhao, Chuang Wang, Lipeng Wang, Lie Wang, Meng Liao, Lei Ye, Ye Zhang, Yue Gao, Bingjie Wang, Huisheng Peng

Issue&Volume: 2021-11-19

Abstract: Li-CO2  batteries are explored as promising power systems to alleviate environmental issues and to implement space applications. However, sluggish cathode kinetics of CO2  reduction/evolution result in low round-trip efficiency and poor cycling stability of the fabricated energy-storage devices. Herein, we design a heterostructued photocathode comprising carbon nanotube and carbon nitride to accelerate cathode reactions of a Li-CO2  battery under illumination. Benefiting from the unique defective structure of carbon nitride and favorable interfacial charge transfer, the photocathode effectively harvests ultraviolet-visible light to generate abundant photoexcited carriers and coordinates energetic photoelectrons/holes to participate in the discharge/charge reactions, leading to efficient photo-energy utilization in decreasing reaction barriers and enhancing thermodynamic reversibility of Li-CO2  battery. The resulting battery delivers high round-trip efficiency of 98.8% (ultralow voltage hysteresis of 0.04 V) and superior cycling stability (86.1% efficiency retention after 100 cycles).

DOI: 10.1002/anie.202114612

Source: https://onlinelibrary.wiley.com/doi/10.1002/anie.202114612