Undesired electrode-electrolyte interactions prevent the use of many high-energy-density cathode materials in practical lithium-ion batteries. Efforts to address their limited service life have predominantly focused on the active electrode materials and electrolytes. Here an advanced three-dimensional chemical and imaging analysis on a model material, the nickel-rich layered lithium transition-...

The mobility and solvation of lithium ions in electrolytes are crucial for the performance and safety of lithium ion batteries. It has been known that a single type of solvent cannot satisfy the requirements of both mobility and solvation simultaneously for electrolytes. Therefore, complex solvent mixtures have been used to optimize both properties. Here we present the effects of density on the...

The demand for portable devices such as cellular phones, PDAs, MP3 players and portable DVD players has grown significantly during the last few years. The portable devices usually include a variety of loads including LCD display, memories, mini microprocessor, Universal Series Bus (USB), and a hard disk drive. These loads require different operating voltages and load currents, and are powered b...

Lithium-air batteries have been considered as ultimate solutions for the power source of long-range electrified transportation, but state-of-the-art prototypes still suffer from short cycle life, low efficiency and poor power output. Here, a lithium-bromine rechargeable fuel cell using highly concentrated bromine catholytes is demonstrated with comparable specific energy, improved power density...

Lithium-oxygen batteries have a great potential to enhance the gravimetric energy density of fully packaged batteries by two to three times that of lithium ion cells. Recent studies have focused on finding stable electrolytes to address poor cycling capability and improve practical limitations of current lithium-oxygen batteries. In this study, the catalyst electrode, where discharge products a...

Scanning ion conductance microscopy imaging of battery electrodes, using the geometry shown in the figure, is a tool for in situ nanoscale mapping of surface topography and local ion current. Images of silicon and tin electrodes show that the combination of topography and ion current provides insight into the local electrochemical phenomena that govern the operation of lithium ion batteries.

Lithium-oxygen batteries, also known as Lithium-air batteries, could possibly revolutionize energy storage as we know. By letting lithium react with ambient oxygen gas very large theoretical energy densities are possible. However, there are several challenges remaining to be solved, such as finding suitable materials and understanding the reaction, before the lithium-oxygen battery could be com...

A multi-dimensional thermal and electrochemical coupled model is developed for Li-ion batteries. The model is capable of predicting the cell internal temperature distribution as well as the average cell temperature evolution. Numerical simulations are performed for a large-size Li-ion cell for electric vehicle applications. Comparisons between the coupled and decoupled model predictions indicat...

Li-ion batteries are used in many applications in everyday life: cell phones, laser pointers, laptops, cordless drillers or saws, bikes and even cars. Yet, there is room for improvement in order to make the batteries smaller and last longer. The Fromm group contributes to this research focusing mainly on nanoscale lithium ion cathode materials. This contribution gives an overview over our curre...