Doped Carbonate Alkaline Battery Cathodes

There is a need for reliable, low-cost energy storage for electric vehicle applications. While advanced Li-ion batteries may possess sufficient power and energy density to be useful for electric vehicles, their high manufacturing and materials costs make them unsuitable outside of a relatively small market niche. Alkaline batteries, one of the most common modern forms of primary battery, are potentially ideal for electric vehicles. These cells depend on a reaction between zinc (Zn) and manganese dioxide (MnO2) to generate energy. This reaction gives alkaline batteries a relatively high energy density and a low cost per kilowatt-hour, but phase transformations occurring during deep discharge prevent recharge. In a typical alkaline battery, useful rechargeability with minimal capacity losses can only be achieved if no more than 10% of the cells capacity is used. [1]

We have developed a new family of electrode materials, new to the literature, which consist of aragonite- or calcite-type carbonates with extensive substitution of manganese atoms on carbon sites. These materials are produced by a simple one-step hydrothermal process, which transforms the surface of a carbon precursor material into an manganese-doped carbonate. Permanganate salts used in the synthesis process result in extensive substitution of manganese atoms into the crystal structure without significant changes in long-range order. These materials have superior capacity, rate capability and cyclability compared to gamma MnO2, with comparable cost. In this presentation, we will describe these materials as we have characterized them via electroanalytical, X-ray and electron microscopy techniques.

References:

1. Shen, Yuwei, and Karl Kordesch. "The mechanism of capacity fade of rechargeable alkaline manganese dioxide zinc cells." Journal of power sources 87.1 (2000): 162-166

Acknowledgements:

This work was performed with financial support from the National Science Foundation CMMI 1402872, Department of Energy ARPA-E RANGE DE-AR0000400, and the Laboratory Directed Research and Development Program of Brookhaven National Laboratory (LDRD-BNL) under Contract No. DE-AC02-98CH 10866 with the U.S. Department of Energy. Use of the National Synchrotron Light Source, Brookhaven National Laboratory, was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, under Contract No. DE-AC02-98CH10886.

Image Captions:

Fig. 1: Structure of manganese-doped barium carbonate (witherite). Barium is represented as green, oxygen as red, manganese as magenta, and carbon as black.