Materials for Energy Storage and Efficiency

International customers, contact your local Sigma-Aldrich office (sigma-aldrich.com/worldwide-offices). Introduction Welcome to the fourth issue of Material Matters™ for 2013 focusing on Materials for Energy Storage and Efficiency. Energy is vital for economic growth. Since the industrial revolution, fossil fuels have served as the major energy source powering the growth of our economy and society. However, increasing global energy demand, coupled with finite supply and long-term environmental effects, means alternative energy sources must provide a larger portion of the energy mix. Alternative energy sources include those that are renewable and environmentally clean, such as solar power, hydrogen-based energy, biofuels, wind, hydroelectric, and geothermal energy. In order for alternative energy to become a major contributor to the global energy supply, however, two significant challenges must be overcome. First, the efficiency of energy generation must improve to the extent that it is at least competitive with existing fossil fuels. Second, lightweight and high-performance storage devices will be required both for mobility and to compensate for the intermittency of power sources such as wind and solar energy generation. Over the last few years, lithium-ion batteries have emerged as one of the most promising energy storage devices due to their high energy density storage capacity. Li-ion batteries are widely used in portable electronics; and currently, numerous research efforts are focused on their large-scale implementation in hybrid and pure electric vehicles. However, these large-scale transportation applications are primarily hindered by performance, safety, and cost of the electrode, electrolyte materials, and other battery components. In our first article, Professors Yves Chabal, Kyeongjae Cho and Christopher Hinkle (USA) discuss certain classes of materials for next-generation cathodes and solid electrolytes that promise new benchmarks for safety and affordability. This article also shows how advanced chemical spectroscopy and first principles modeling can be utilized to study the interface reactions between the new electrode and electrolyte materials to improve battery performance and stability. In the second article, Professors Xuefeng Song and Lian Gao (China) review the next generation of anode materials designed to meet the high energy demands of Li-ion batteries for the hybrid and electric automobile market. The article focuses on silicon as a promising replacement material for graphite anodes. Advantages of silicon anodes include high theoretical capacity and relatively low working potential, as well as low cost and toxicity. The authors also describe several viable solutions to the problem of volumetric change encountered during the charge/discharge cycle that is …