Chinese Scientists Achieve Breakthrough in All-Solid-State Lithium Battery Research

Imagine if your smartphone battery were not only safer and smaller but also lasted much longer on a single charge—how amazing would that be! Recently, a research team from the Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, made a new breakthrough in the field of all-solid-state lithium batteries. This advancement could potentially make the dream of miniaturized, long-lasting electronic devices a reality. The findings were published on July 31 in the international academic journal Nature Energy.

Lithium-ion batteries, which power smartphones, laptops, and other electronic devices, typically store and release energy using liquid electrolytes. Now, scientists are exploring a new type of battery— the all-solid-state lithium battery. Unlike conventional batteries, these batteries use solid electrolytes instead of liquid ones, making them safer and less prone to leaks or fires.

Although all-solid-state lithium batteries sound ideal, they face several challenges in development. The main issue lies in the difficulty of achieving perfect chemical and physical compatibility among different materials within the battery‘s cathode, which leads to various interfacial problems that can affect energy density and lifespan. To address this, the research team developed a new material—homogeneous cathode material (Lithium Titanium Germanium Phosphorus Sulfur Selenium, LTGPSSe).

This new material offers several advantages over traditional materials:

1. High Conductivity: The new material boasts high ionic and electronic conductivity, exceeding that of conventional cathode materials (layered oxide cathode materials) by over 1,000 times. This means that even without relying on conductive additives, the cathode can efficiently complete the charge-discharge process, significantly enhancing the overall battery performance.

2. High Discharge Capacity: The discharge capacity of the new material reaches 250 mAh/g, surpassing the high-nickel cathode materials currently in use. This allows the battery to store more energy for the same weight or volume, extending its operating time between charges and enabling the design of more compact devices.

3. Low Volume Change: During charge and discharge cycles, the new material experiences only a 1.2% volume change, much lower than the 50% seen in traditional materials (layered oxide cathode materials). This minimal volume change helps maintain structural stability, thereby extending the battery‘s lifespan.

4. High Energy Density: The energy density of all-solid-state lithium batteries using this new material reaches 390 Wh/kg, 1.3 times higher than that of currently reported long-cycle all-solid-state lithium batteries.

5.Long Lifespan: All-solid-state lithium batteries made with this material can achieve over 10,000 cycles with a long cycle life. Even after 5,000 cycles of charging, the battery retains 80% of its initial capacity, providing ample power for a longer period.

This research offers crucial technological support for developing high-energy-density, long-lifespan energy storage devices, providing safe and durable power sources for electric vehicles, energy storage grids, deep-sea, and deep-space equipment. It also holds significant implications for developing new energy storage systems.