The Development and Benefits of Cost-Effective Solid-State Electrolyte for Lithium Batteries

A team of researchers, led by Prof. Ma Cheng from the University of Science and Technology of China (USTC), have developed a promising new type of solid-state electrolyte, marking considerable progress in the field of lithium battery technology.

All-solid-state lithium batteries (ASSLBs) are touted as the future of electric vehicles, with the potential to revolutionize the auto industry. These batteries hold several advantages over current commercial lithium-ion batteries. Key among these is the significantly improved safety of these batteries, which address the important issue of safety concerns posed by the extant lithium-ion batteries. Additionally, ASSLBs hold a much higher potential for enhancing energy density.

The construction of functional ASSLBs largely depends on the use of suitable solid-state electrolytes. This poses a challenge as the high-performance solid-state electrolytes that currently exist are generally too costly for commercial use.

Addressing this issue, the research team successfully developed a new type of solid-state electrolyte known as lithium zirconium oxychloride (LZCO). One of the substantial advantages of this new electrolyte is its low cost, which stems from the fact that it can be synthesized from inexpensive, widely-available compounds such as lithium hydroxide monohydrate, lithium chloride, and zirconium chloride. As a result, the cost of LZCO production can be as low as $11.60 per kilogram, a fraction of the costly high-performance sulfide and chloride solid-state electrolytes, which are generally priced above $190 per kilogram.

Lithium zirconium oxychloride also offers competitive performance levels. For instance, the electrolyte exhibits room-temperature ionic conductivity of up to 2.42 mS cm-1, one of the highest conductivities reported among all kinds of solid-state electrolytes thus far. Additionally, LZCO shows impressive compressibility, achieving almost 94.2% density under 300 MPa, outperforming the compression capabilities of sulfide and chloride solid-state electrolytes, which typically fall below 90% at the same pressure level.

Testing revealed that overall, the performance of LZCO was on par with some of the most advanced sulfide and chloride solid-state electrolytes available. Notably, the nickel-rich layered cathode-enhanced ASSLB created with LZCO exhibited exceptional stability and was able to complete over 2,000 cycles at room temperature when tested under 12-minute fast charging conditions.

The creation of this new material is a significant advancement in the development of cost-effective, efficient solid-state electrolytes. This breakthrough brings the prospect of commercializing all-solid-state lithium batteries significantly closer, promising a dynamic transformation of the electric vehicle industry in the near future.