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Lithium-ion batteries (LIBs) are being used in locations and applications never imagined when they were first conceived. To enable this broad range of applications, it has become necessary for LIBs to be stable to an ever broader range of conditions, including temperature and energy. Unfortunately, while negative electrodes have received a great deal of focus in electrolyte development, stabilization of positive electrodes remains an elusive target. Here, we report a novel additive that shows the ability to protect positive electrodes against elevated temperatures and voltages. This additive can be used in small quantities, and its targeted behavior allows it to remain functional in complex electrolyte packages. This can prove an effective approach to targeting specific aspects of cell performance.

The thermal degradation of electrolytes containing lithium hexafluorophosphate (LiPF6) is a well-studied subject. However, practical application of the knowledge is difficult since the effects of t...

We investigated the static reactions of highly delithiated Li(Ni1/3Mn1/3Co1/3)O2, Li(Ni0.5Mn0.3Co0.2)O2, Li(Ni0.6Mn0.2Co0.2)O2, and Li(Ni0.8Mn0.1Co0.1)O2 positive electrodes with 2,3-butanedione an...

We report the fabrication and characterization of photochromic dye sensitized solar cells that possess the ability to change color depending on external lighting conditions. This device can be used as a “smart” window shade that tints, collects the sun's energy, and blocks sunlight when the sun shines, and is completely transparent at night.

Self-Assembling 1,4,5,8-Naphthalentetracarboxylic Diimide- Microwires for Optoelectronic Devices The widespread use of organic electronic devices requires simple yet effective synthesis techniques to create materials with low-cost and high performance. We report the solution phase crystallization of 1,4,5,8-naphthalenetetracarboxylic diimide (NDI) microwires from dimethylsulfoxide. These microwires were characterized by means of scanning electron microscopy, thermal analysis, and infrared and fluorescence spectroscopies. The microwires were also characterized for their electrical properties and were shown to exhibit an n-type semi-conductive property as well as photoresponsive changes in conductivity. The electron mobility within the NDI microwires was determined to be lower than previous literature reports, yet the combination of photo-responsive changes in electrical conductivity may hold promise of photo-sensors, organic light-emitting diodes, and other optoelectronic devices.

A proton-conductive material based on a crystalline assembly of trimesic acid and melamine (TMA⋅M, see picture) is reported. Because of the ordered structure of the assembly, the water-saturated proton conductivity for the TMA⋅M assembly is 5.5 S cm(-1) , which is the highest proton conductivity measured to date. This exceptionally high conductivity and low-cost fabrication of the material make applications feasible for fuel-cell devices.