Battery electrode materials are required to meet multiple demands simultaneously. They must effectively conduct charges to facilitate ions’ movement between electrodes. Furthermore, their structure should permit ion mobility until those ions reach their designated storage sites. The accumulation of ions leads to expansion, which generates mechanical stresses capable of causing gradual deterioration in the electrode’s structure.
Due to the challenges of designing a single material that can fulfill all these roles, many electrodes are constructed from composite materials. These composites typically involve one chemical for ion transfer, another for ion storage, and possibly a third to enhance conductivity. However, this complexity can introduce additional challenges, particularly at the interfaces between different materials, which may slowly reduce the battery’s capacity over time.
In light of these issues, a research team has proposed a new material that appears to address all the necessary functions. This innovative material demonstrates reasonable conductivity, facilitates the movement of lithium ions to their storage sites, and is composed of inexpensive and readily available elements. Notably, it boasts the capability of self-healing, which helps repair damage incurred during the charge and discharge cycles.
High capacity
The research team, largely based in China, aimed to simplify the design of cathodes. They note that traditional composite cathode designs, which typically incorporate an active material, a catholyte, and additives for electrical conductivity, can become encumbered by a significant volume of electrochemically inactive components. To overcome this limitation, the researchers proposed the creation of an all-in-one material that minimizes the need for these additional components.
Prior research highlighted the effectiveness of chlorine-based compounds, which permit ion movement through the material while lacking in electrical conductivity. To enhance their approach, the team experimented with pre-loading one of these compounds with lithium, ultimately focusing on iron chloride due to its low cost.
