Electrospining Machine: Wuhan University of Technology Prof. Li-Qiang Mai & Prof. Lin Xu AFM review: Nanowires for solid-state lithium batteries

Background

An important way to obtain high safety and high energy density lithium batteries is to develop solid-state electrolytes (SSEs). However, lithium ion transport and interfacial stability issues limit the construction of solid-state lithium batteries (SSLBs). Therefore, the development of fast ionic conductors with high electrochemical performance and chemical stability is crucial for SSLBs. Nanowires (NWs) have a high aspect ratio to maintain carrier transport along the radial direction, and thus are widely used in SSLBs to improve ion transport efficiency, mechanical properties, thermal stability, flame retardancy, and interfacial stability between the electrode and electrolyte, thereby improving the cycling stability and safety of SSLBs.

Recently, Prof. Li-Qiang Mai and Prof. Lin Xu of Wuhan University of Technology published a review on the innovative application of nanowires (NWs) in improving the performance and safety of solid-state lithium batteries (SSLBs). The research was published in the journal Advanced Functional Materials under the title “Nanowires for Solid-State Lithium Batteries”.

The main point of this paper

1.This paper systematically reviews the application of nanowires from rational design and synthesis strategies to composite cathode and anode materials and solid-state electrolytes in solid-state lithium batteries.

2. The key role of nanowires in electrodes and the mechanism of performance enhancement of solid-state electrolytes by introducing nanowires are summarized in detail.

3. Finally, the existing challenges and expected prospects for future development of nanowire-based solid-state lithium batteries are summarized and outlined.

What are the advantages of using nanowires in solid-state lithium batteries (SSLBs)?

1. Enhanced ionic conductivity:

Nanowires provide a high aspect ratio, which helps conduct ions efficiently along their length, thus improving the overall ionic conductivity of the battery.

2. Mechanical Stability:

The flexibility of nanowires helps to accommodate volume changes during the charge/discharge cycle, reducing the risk of electrode rupture and maintaining structural integrity.

3. Increased surface area:

The large specific surface area of nanowires allows for higher active material loading, which enhances electrochemical reaction kinetics and improves battery performance.

4. Improve interfacial stability:

 Nanowires can form a stable interface between the electrodes and solid state electrolytes (SSEs), which is critical for minimizing charge transfer resistance and enhancing battery efficiency.

5. Mitigates volume expansion:

The unique morphology of nanowires helps mitigate the volume expansion that occurs during the lithiation/de-lithiation process, thus maintaining good contact between the electrode and the electrolyte.

6. Facilitate the formation of composite structures:

Nanowires can be used as scaffolds or carriers for other materials, making it possible to build composite electrodes that combine the advantages of different materials to optimize performance.

What are the challenges in the development of nanowire-based solid-state lithium batteries (SSLBs)?

1. Ionic and electronic conductivity:

Achieving continuous and efficient ionic and electronic conductive channels in electrode materials and solid state electrolytes (SSEs) remains a major challenge. The interface between the nanowires and the electrolyte must facilitate efficient ion transport.

2. Interfacial stability:

The transition from liquid to solid electrolyte changes the dynamics of the electrode/electrolyte interface, which may lead to increased contact resistance and interfacial instability. Side reactions between the electrode material and SSE may further exacerbate this problem.

3. Mechanical stability:

Enhanced mechanical properties of SSE are required to withstand the stresses associated with lithium ion embedding and detachment. Nanowires must maintain structural integrity during cycling to prevent electrode fragmentation and loss of contact with the electrolyte.

4. Scalability and Fabrication:

The synthesis and integration of nanowires into battery components must be scalable for commercial production. Current manufacturing methods may not be suitable for large-scale production, which may hinder the practical application of nanowire-based SSLBs.

5. Thermal stability and safety:

Although nanowires can improve thermal stability, it is critical to ensure that SSEs operate safely at high temperatures without thermal runaway. The materials used must have good thermal stability and flame retardancy.

6. Cost and Material Availability:

Materials for nanowires and solid state electrolytes can be expensive or difficult to obtain on a large scale. Reducing cost while maintaining performance is a significant barrier to commercialization.

7. Cycle life and performance degradation:

Ensuring long cycle life and minimizing performance degradation over time is critical to the viability of SSLBs. An in-depth study of the mechanical and electrochemical stability of nanowires in repeated charge/discharge cycles is required

Originallink: https://doi.org/10.1002/adfm.202412548