High-Energy and High-Power Electrochemical Energy Storage Based on Dual Intercalation/Radical Electrodes

Li-ion and related battery technologies will be important for years to come. However, society needs energy storage that exceeds the energy and power of common Li-ion batteries.^1,2 Many prospective applications of batteries require improving both energy density and rate capability. The simultaneous improvement of these two parameters is not sufficiently addressed by state-of-the-art approaches. High capacity lithium intercalation materials often exhibit poor ionic and electronic conductivity which limit rate capability. Battery electrodes based on polymers bearing organic free radicals allow for exceptionally high rates but fall short in meeting energy density requirements.^3,4

Here, we combine the advantages of both storage principles, to form battery electrodes capable of delivering the capacity of the high-energy intercalation material and intermittently the high rate capability of the radical material. First, we must understand the processes that occur in the cell on discharge and charge to fully take advantage of the potential of the concept.

We will discuss recent results on the detailed elucidation of the charge transfer mechanism in the so formed dual radical/intercalation electrodes, materials aspects, thermodynamic and kinetic considerations. We combine synthetic, spectroscopic and advanced electroanalytical methods to gain insight into the governing processes.

1. B. Scrosati, J. Hassoun, Y.-K. Sun, Energy Environ. Sci., 4, 3287 (2011).

2. M.M. Thackeray, C. Wolverton, E.D. Isaacs, Energy Environ. Sci., 5, 7854 (2012).

3. K. Oyaizu, H. Nishide, Adv. Mat., 21, 2339 (2009).

4. T. Janoschka, M.D. Hager, U.S. Schubert, Adv. Mat., 24, 6397 (2012).