Recent progress on the low and high temperature performance of nanoscale engineered Li-ion battery cathode materials.

Lithium ion batteries (LIB) are the domain power house that gratifies the growing energy needs of the modern society. Statistical records highlight the future demand of LIB for transportation and other high energy applications. Cathodes play a significant role in enhancement of electrochemical performance of a battery, especially in terms of energy density.

Nanoscale-engineered LiCoOas a high energy cathode for wide temperature lithium-ion battery applications-role of coating chemistry and thickness.

Extending the charge cutoff voltage of LiCoO(LCO) beyond 4.2 V is considered as a key parameter to obtain higher energy densities. Following gaps have been identified based on a thorough literature survey especially for higher cutoff voltage of nanoscale engineered LCO cathodes, (i) different metal oxides and metal fluoride surface coatings have been mostly done independently by different groups, (ii) room temperature performance was the focus with limited investigations at high temperature, (iii) nonexistence of low temperature cycling studies and (iv) no reports on high rate capability of LCO beyond 4.

Surface-Engineered LiTiO Nanostructures for High-Power Li-Ion Batteries.

Materials with high-power charge-discharge capabilities are of interest to overcome the power limitations of conventional Li-ion batteries. In this study, a unique solvothermal synthesis of LiTiO nanoparticles is proposed by using an off-stoichiometric precursor ratio. A Li-deficient off-stoichiometry leads to the coexistence of phase-separated crystalline nanoparticles of LiTiO and TiO exhibiting reasonable high-rate performances.

Focused Ion Beam Fabrication of LiPON-based Solid-state Lithium-ion Nanobatteries for In Situ Testing.

Solid-state electrolytes are a promising replacement for current organic liquid electrolytes, enabling higher energy densities and improved safety of lithium-ion (Li-ion) batteries. However, a number of setbacks prevent their integration into commercial devices. The main limiting factor is due to nanoscale phenomena occurring at the electrode/electrolyte interfaces, ultimately leading to degradation of battery operation.

Interface-engineered LiTiO-TiO dual-phase nanoparticles and CNT additive for supercapacitor-like high-power Li-ion battery applications.

The single-pot synthesis of dual-phase spinel-LiTiO and anatase-TiO (LTO-TiO) nanoparticles over all the phase fractions ranging from pure LTO to pure TiO is conducted. Carrying out the process over the complete range enabled the identification of a unique weight ratio of 85:15 (LTO:TiO), providing the best combination of capacity, rate capability and cycling stability. We show that for this composition dual-phase nanoparticles have a predominant interfacial orientation of (111)∣∣(004) , while it is (111)∣∣(101) for other compositions.

In Situ STEM-EELS Observation of Nanoscale Interfacial Phenomena in All-Solid-State Batteries.

Behaviors of functional interfaces are crucial factors in the performance and safety of energy storage and conversion devices. Indeed, solid electrode-solid electrolyte interfacial impedance is now considered the main limiting factor in all-solid-state batteries rather than low ionic conductivity of the solid electrolyte. Here, we present a new approach to conducting in situ scanning transmission electron microscopy (STEM) coupled with electron energy loss spectroscopy (EELS) in order to uncover the unique interfacial phenomena related to lithium ion transport and its corresponding charge transfer.

Effects of laser energy and wavelength on the analysis of LiFePO₄ using laser assisted atom probe tomography.

The effects of laser wavelength (355 nm and 532 nm) and laser pulse energy on the quantitative analysis of LiFePO₄ by atom probe tomography are considered. A systematic investigation of ultraviolet (UV, 355 nm) and green (532 nm) laser assisted field evaporation has revealed distinctly different behaviors. With the use of a UV laser, the major issue was identified as the preferential loss of oxygen (up to 10 at%) while other elements (Li, Fe and P) were observed to be close to nominal ratios.

Interface Limited Lithium Transport in Solid-State Batteries.

Understanding the role of interfaces is important for improving the performance of all-solid-state lithium ion batteries. To study these interfaces, we present a novel approach for fabrication of electrochemically active nanobatteries using focused ion beams and their characterization by analytical electron microscopy. Morphological changes by scanning transmission electron microscopy imaging and correlated elemental concentration changes by electron energy loss spectroscopy mapping are presented.