China News Network published a blog post on November 26, reporting that Professor Tan Peng's team at the University of Science and Technology of China discovered a key factor that breaks through the bottleneck of lithium-oxygen battery capacity. The relevant findings were published in Nature Communications.

Project Background

Lithium-oxygen batteries have long been considered a revolutionary technology for energy storage due to their ultra-high theoretical energy density.

In recent years, researchers have made significant advancements in the high-rate performance and stability of lithium-oxygen batteries, yet the actual capacity has far from reached the theoretical value. The primary reason lies in the insufficient utilization of the internal space within the porous cathode.

Complex couplings of phase change, mass transfer, and Faraday reactions, along with technical limitations in accurately characterizing the electrode interior, present challenges in revealing cathode processes and breaking through capacity bottlenecks.

Project Introduction

The key to resolving the aforementioned issue lies in establishing a connection between the micro-behavior of the discharge products lithium peroxide and its electrochemical properties. In this research work, to exclude the influence of factors such as solvents and catalysts on the behavior of lithium peroxide, researchers adjusted the initial kinetic state by modifying the lithium ion concentration.

The research team discovered that by adjusting the lithium ion concentration and regulating the matching degree between transport and nucleation dynamics, the discharge capacity of lithium-oxygen batteries can be significantly enhanced.

Through visualized electrode and cross-scale mathematical models, the research team further explored the distribution characteristics of lithium peroxide. In a 0.5 molar per liter electrolyte solution, lithium peroxide particles exhibit an inverse oxygen gradient distribution, indicating an optimal balance in nucleation and transport dynamics, thereby achieving the maximum discharge capacity.

The key to breaking through the capacity bottleneck is not just about accelerating oxygen transmission, but also about maintaining material transport deep within the electrodes. The researchers explain that this study provides theoretical guidance for achieving high-energy density lithium-air batteries.

Breaking the Capacity Bottleneck of Lithium-Oxygen Batteries through Rec...nceptualizing transport and nucleation kinetics | Nature Communications