Scientists at the Tokyo Institute of Technology (Tokyo Tech have experimentally demonstrated that pure compounds increase the capacity of a solid-state lithium battery, the American Chemical Society writes.
Liquid lithium-ion batteries can be found everywhere today: they are ubiquitous due to their widespread use in most everyday mobile devices. While they offer significant benefits, liquid-based batteries carry a significant risk. This has become apparent to the public in recent years after reports of smartphones catching fire due to design errors that have led to leakage and combustion of the battery fluid.
Other drawbacks – manufacturing cost, durability and capacity – prompted scientists to explore another technology: solid-state lithium batteries (SSLB). SSLBs are made up of solid electrodes and a solid electrolyte that exchange lithium (Li) ions during charging and discharging. Their higher energy density and security make SSLB very powerful sources.
However, there are still many technical issues that hinder the commercialization of SSLB. For the current study, researchers conducted a series of experiments and concluded that it could take SSLB performance to the next level. Professor Taro Hitosugi of Tokyo Tech, who led the study, explains their motivation: “LiNi 0.5 Mn 1.5 O 4 (LNMO) is a promising material for the SSLB positive electrode as it can generate relatively higher voltages. In this study, we have shown a battery operates at 2.9 and 4.7 volts while providing high capacity, stable cycling and low electrolyte/electrode resistance.”
Previous research has shown that creating a clean electrolyte / electrode interface is necessary to achieve low interface resistance and fast charging of LNMO-based SSLBs. The scientists also noted that Li ions spontaneously migrated from the Li3PO4 (LPO) electrolyte into the LNMO layer during manufacture, forming the LiNi 0.5 Mn 1.5 O 4 (L 2 NMO) phase in LNMO with unknown distribution and influence on battery performance.
Strikingly, the metal-clean interface made it easy to intercalate and deintercalate Li during SSLB charging and discharging. As a result, the SSLB capacity with a clean interface was double that of conventional LNMO-based batteries.