Current lithium-oxygen (Li-O₂) batteries suffer from large charge overpotentials related to electronic resistivity of the insulating lithium peroxide (Li₂O₂) discharge product. One potential solution to this challenge is the stabilization of the lithium superoxide (LiO₂) discharge intermediate, which has much higher electronic conductivity compared to Li₂O₂. Cathodes based on small iridium (Ir) nanoparticles have been recently used in a Li-O₂ battery to successfully stabilize the LiO₂ product, however, the LiO₂ had a short lifetime. In the previous study, researchers found that the LiO₂ was stabilized on Ir₃Li surfaces which were formed from Ir nanoparticles during battery operation. Little is known about the electronic properties of Ir₃Li and its role in stabilizing LiO₂ product formation. This work provides the first study of the electronic properties of Ir₃Li, which was thermally synthesized in bulk prior to implementation on the reduced graphene oxide (rGO) cathode of a Li-O₂ cell. The bulk Ir₃Li was found to have comparable electrical conductivity to Ir metal, possess metal-like magnetic properties, and has an affinity towards O₂ adsorption. The LiO₂ discharge product formed from the Li-O₂ battery discharge was characterized using Raman spectroscopy, titration, along with a comprehensive transmission electron microscopy (TEM) study. This analysis revealed the formation of ultra-nanocrystalline LiO₂ particles greater than 200 nm. This result was attributed to the use of large micron sized Ir₃Li particles, which could stabilize larger LiO₂ particles compared to previous cathodes that utilized Ir nanoparticles that partially converted to Ir₃Li during cycling. These results demonstrate that cathode properties can be modified to stabilize the bulk LiO₂ discharge product, which can be useful for the further development of LiO₂-based Li-O₂ batteries.

当前的锂氧 (Li-O ₂ ) 电池存在与绝缘过氧化锂 (Li ₂ O ₂ ) 放电产物的电阻率相关的大充电过电位。这一挑战的一个潜在解决方案是稳定超氧化锂 (LiO ₂ ) 放电中间体，与 Li ₂ O ₂相比，它具有更高的电子导电性。最近，基于小铱 (Ir) 纳米粒子的阴极已用于 Li-O ₂电池以成功稳定 LiO ₂产品，但是，LiO ₂的寿命很短。在之前的研究中，研究人员发现 LiO ₂在电池运行期间由 Ir 纳米颗粒形成的Ir ₃ Li 表面上稳定。关于 Ir ₃ Li的电子特性及其在稳定 LiO ₂产物形成中的作用知之甚少。这项工作首次对 Ir ₃ Li的电子特性进行了研究，在Li-O ₂电池的还原氧化石墨烯 (rGO) 阴极上实施之前，该锂是大量热合成的。发现块状 Ir ₃ Li 具有与金属 Ir 相当的电导率，具有类似金属的磁性，并且对 O ₂吸附具有亲和力。由 Li-O ₂形成的 LiO ₂放电产物电池放电使用拉曼光谱、滴定以及综合透射电子显微镜 (TEM) 研究进行表征。该分析揭示了大于200nm的超纳米晶LiO ₂颗粒的形成。这一结果归因于使用大微米尺寸的 Ir ₃ Li 颗粒，与使用在循环过程中部分转化为 Ir ₃ Li 的Ir 纳米颗粒的先前阴极相比，它可以稳定更大的 LiO ₂颗粒。这些结果表明，可以修改正极性能以稳定体相 LiO ₂放电产物，这对于进一步开发 LiO ₂基 Li-O ₂很有用 电池。