†Department of Energy Engineering, Hanyang University, Seoul, 133-791, Republic of Korea.
ACS Nano. 2015 Apr 28;9(4):4129-37. doi: 10.1021/acsnano.5b00267. Epub 2015 Apr 2.
Although lithium-oxygen batteries are attracting considerable attention because of the potential for an extremely high energy density, their practical use has been restricted owing to a low energy efficiency and poor cycle life compared to lithium-ion batteries. Here we present a nanostructured cathode based on molybdenum carbide nanoparticles (Mo2C) dispersed on carbon nanotubes, which dramatically increase the electrical efficiency up to 88% with a cycle life of more than 100 cycles. We found that the Mo2C nanoparticle catalysts contribute to the formation of well-dispersed lithium peroxide nanolayers (Li2O2) on the Mo2C/carbon nanotubes with a large contact area during the oxygen reduction reaction (ORR). This Li2O2 structure can be decomposed at low potential upon the oxygen evolution reaction (OER) by avoiding the energy loss associated with the decomposition of the typical Li2O2 discharge products.
虽然锂-氧电池由于具有极高的能量密度而引起了相当大的关注，但与锂离子电池相比，其能量效率低和循环寿命差，限制了它们的实际应用。在这里，我们提出了一种基于碳化钼纳米颗粒（Mo2C）分散在碳纳米管上的纳米结构阴极，其电效率显著提高到 88%，循环寿命超过 100 次。我们发现，Mo2C 纳米颗粒催化剂有助于在氧还原反应（ORR）过程中形成在 Mo2C/碳纳米管上具有大接触面积的分散良好的过氧化锂纳米层（Li2O2）。这种 Li2O2 结构可以在析氧反应（OER）时通过避免与典型 Li2O2 放电产物分解相关的能量损失，在低电位下分解。
