Chinese and German scientists announced a significant breakthrough in the development of lithium-gray batteries. A new approach, presented in the journal Nature, demonstrates the improved stability and performance of these batteries using a solid electrolyte.
Lithium has been a key material for creating batteries for decades. However, sulfur compounds, despite the higher lithium storage capacity compared to silicon, faced several restrictions. These included low conductivity, material expansion during lithium storage, and the formation of soluble intermediate compounds that reduced battery effectiveness and durability.
The researchers aimed to eliminate these challenges by utilizing a solid electrolyte with a porous atomic structure that effectively conducts ions while limiting the movement of sulfur-containing compounds. This innovative approach significantly increases the charging efficiency and slows down the self-discharge process.
The breakthrough was made possible through the development of a glass-shaped mixture of boron, sulfur, lithium, phosphorus, and iodine. Scientists noted that iodine accelerates electron transfer and enhances reaction speed on the electrodes.
Impressive test results revealed that even with high-speed charging (50°C, full charge in a minute), the batteries retained half of their capacity. After 25,000 charging cycles, the batteries maintained over 80% of their initial capacity, far exceeding traditional lithium-ion batteries that typically wear out after around 1000 cycles.
Despite these advancements, concerns remain about energy density. Experimental calculations only considered the weight of sulfur, leading to uncertainty about the total mass and volume of the batteries. This limitation may restrict their use in compact devices like smartphones and electric cars. However, they could prove to be a groundbreaking solution for stationary energy storage systems due to their high durability and rapid charging capabilities.
If mass production is achieved, lithium-gray batteries have the potential to revolutionize the approach to creating energy-dense and reliable energy storage systems.