Introducing Quick Detection of Lithium Batteries

Lithium-ion batteries (LIBs) have been widely adopted in portable electronic devices due to their long lifespan, high specific capacity, and high power density. They are also used in newly developed electric vehicles and are expected to become one of the primary power sources in the future. As the demand for power from all these devices continues to rise, the performance of lithium-ion batteries has become a hot topic. Researchers increasingly focus on the rapid detection, characterization, and quality control of lithium-ion battery materials.

The theoretical energy density of commercial lithium battery systems based on graphite anodes (600 Wh/kg) cannot meet the increasing energy storage needs of high-power-consuming electric vehicles, among others. Replacing the graphite anode (theoretical capacity: 372 mA h g⁻¹) with a high-capacity phosphorus anode (2596 mA h g⁻¹) can further improve the energy density of the battery system. Compared to the graphite anode (lithiation potential of 0.1 V), the phosphorus anode has a safer lithiation potential (0.7 V), which better avoids lithium dendrite issues caused by overpotential during the battery cycling process. Therefore, the phosphorus anode is considered one of the high-capacity, fast-charging anode materials with great research potential.

Among the three main allotropes of phosphorus, black phosphorus is expensive, and white phosphorus is toxic. Red phosphorus, which is non-toxic, stable in air, abundant in supply, and inexpensive, is seen as the most commercially viable phosphorus anode. In addition to research on electrode materials, the study of electrolytes is also crucial. The implementation of phosphorus-based lithium batteries using traditional lithium hexafluorophosphate (LiPF₆) electrolyte is influenced by three main factors: i) The significant volume expansion (~300%) of the phosphorus anode during lithiation/delithiation can easily lead to the pulverization and detachment of active materials, as well as an unstable solid-electrolyte interphase (SEI), which is unfavorable for long-term cycling stability; ii) LiPF₆ is extremely sensitive to moisture, alcohol, and water, and will self-catalyze decomposition into reactive substances (such as HF), further promoting side reactions with the electrodes, electrolyte, and binders; iii) Safety issues arising from the highly flammable and volatile nature of traditional electrolytes. Previous work has focused on designing various nanostructured electrodes, with little consideration given to optimizing electrolytes, resulting in unsatisfactory electrochemical performance at high current densities (generally greater than 1 A g⁻¹). There are few reports on efficient electrolyte systems specifically for phosphorus anodes. Therefore, designing and optimizing safe and efficient electrolytes is essential for fast-charging lithium-ion batteries (LIBs).