Exploring manganese-based batteries for grid-scale energy storage

Powering our electrical grid with renewable energy will require significant grid-sized battery storage. Existing battery technology is unlikely to be sufficient, but aqueous manganese (Mn)-based batteries are promising alternatives. These batteries are cheap, safe, and reversible. They are also highly varied, featuring multiple redox couples and reaction types, making this field incredibly complex.

Lei et al. cut through this complexity and provided an overview of each battery type, described its advantages and limitations, and discussed possible applications.

“The dramatic property differences in the multivalent Mn species make their mechanisms and challenges varied, involving solid-liquid deposition/dissolution reactions, liquid/liquid conversion reactions, and solid intercalation/deintercalation reactions,” said author Yi-Chun Lu. “This complexity also brings many opportunities for developing practical next-generation Mn-based batteries.”

For each battery type, the authors explore these potential opportunities and the challenges that need to be overcome. For instance, Mn metal electrodes could be used in high-energy aqueous batteries if their reversibility and deposition efficiency can be improved. Mn²⁺/MnO₂-based batteries have high voltage but poor control of protons. Mn²⁺/Mn³⁺ and MnO₄^2-/MnO₄⁻-based flow batteries show poor stability but offer high voltage and volumetric capacity.

“The reaction type and working conditions (potential range, pH value, etc.) differ for each reaction, and sometimes they may co-exist in one battery system, complicating the analysis,” said Lu. “Deciphering the exact reaction applied in a specific battery system and optimizing it based on the reaction type is of vital importance.”

The team is hopeful that these technologies will continue to be improved and that Mn-based batteries will become a valid solution for grid-sized energy storage.

Source: “Emerging aqueous manganese-based batteries: Fundamental understanding, challenges, and opportunities,” by Jiafeng Lei, Liwei Jiang, and Yi-Chun Lu, Chemical Physics Reviews (2023). The article can be accessed at https://doi.org/10.1063/5.0146094 .