Increasing energy consumption, shortages of fossil fuels, and concerns about the environmental impact of energy use, especially emissions of carbon dioxide, give fresh impetus to the development of renewable energy sources. With the advent of renewable energy, it is now indispensable that efficient energy storage systems have to be developed. One of the most promising storage systems to be employed in stationary energy storage applications are lithium-based batteries (LIB), mainly due to their high energy density, high power, and nearly 100 % efficiency. Within the scope of this paper, we carry out a patent search using the patent database PatBase® to assess the development status of LIB technology. The analysis of the generated patent sample reveals disproportionately high growth rates in LIB patent applications over the last years compared to other selected energy-related technologies. Breaking down patent application growth by the different components of LIB shows the principal drivers of growth. The purpose of this paper is to provide current research trends and prospects for the main LIB materials and designs.

Current research trends and prospects among the various materials and designs used in lithium-based batteries

A lithium metal oxide positive electrode for a non-aqueous lithium cell is disclosed. The cell is prepared in its initial discharged state and has a general formula xLiMO 2 .(1−x)Li 2 M′O 3 in which 0<x<1, and where M is one or more ion with an average trivalent oxidation state and with at least one ion being Mn or Ni, and where M′ is one or more ion with an average tetravalent oxidation state. Complete cells or batteries are disclosed with anode, cathode and electrolyte as are batteries of several cells connected in parallel or series or both.

Lithium metal oxide electrodes for lithium cells and batteries

A high capacity lithium secondary battery with excellent safety is provided by suppressing expansion of a negative electrode active material during charge and increasing the content of a heat-resistant resin in a separator relative to conventional one. The lithium secondary battery includes: a negative electrode active material that comprises compound particles containing at least one metal element selected from the group consisting of Si, Sn, Al, and Zn; and a separator that has a first porous layer comprising polyolefin and a second porous layer comprising a heat-resistant resin. The separator contains 10 to 60 parts by weight of the second porous layer per 100 parts by weight of the first porous layer.

Lithium Secondary Battery

Increasing electrode thickness, thus increasing the volume ratio of active materials, is one effective method to enable the development of high energy density Li-ion batteries. In this study, an energy density versus power density optimization of LiNi0.8Co0.15Al0.05O2 (NCA)/graphite cell stack was conducted via mathematical modeling. The energy density was found to have a maximum point versus electrode thickness (critical thickness) at given discharging C rates. The physics-based factors that limit the energy/power density of thick electrodes were found to be increased cell polarization and underutilization of active materials. The latter is affected by Li-ion diffusion in active materials and Li-ion depletion in the electrolyte phase. Based on those findings, possible approaches were derived to surmount the limiting factors. The improvement of the energy–power relationship in an 18,650 cell was used to demonstrate how to optimize the thick electrode parameters in cell engineering.

Understanding limiting factors in thick electrode performance as applied to high energy density Li-ion batteries

An activated electrode for a non-aqueous electrochemical cell is disclosed with a precursor of a lithium metal oxide with the formula xLi2MnO3•(1-x)LiMn2-yMyO4 for O<x<1 and O≤y<1 in which the Li2MnO3 and LiMn2-yMyO4 components have layered and spinel-type structures, respectively, and in which M is one or more metal cations. The electrode is activated by removing lithia, or lithium and lithia, from the precursor. A cell and battery are also disclosed incorporating the disclosed positive electrode.

Manganese oxide composite electrodes for lithium batteries

A cathode composition for a lithium-ion battery having the formula Li[M 1 (1-x) Mn x ]O 2 where 0<x<1 and M 1 represents one or more metal elements, with the proviso that M 1 is a metal element other than chromium. The composition is in the form of a single phase having an O3 crystal structure that does not undergo a phase transformation to a spinel crystal structure when incorporated in a lithium-ion battery and cycled for 100 full charge-discharge cycles at 30° C. and a final capacity of 130 mAh/g using a discharge current of 30 mA/g.

Jeffrey R. Dahn

Papers

Cathode compositions for lithium ion batteries