Alkaline Zn-MnO2 technology is one of the oldest battery chemistries applied for commercial primary batteries and is still produced nowadays in large quantities with high specific energy (130 Wh∙kg-3 and 400 Wh·dm-3). Making this battery chemistry rechargeable is a challenge worthy to take up.
Rechargeable ZnMnO2 battery technologies are promising candidates for stationary energy storage applications, due to their use of abundant and low environmental impacting materials, low cost and high safety. The main issue hampering their wide implementation is the low cycle life, mostly due to instability of MnO2 cathode.
The best results in the literature on alkaline rechargeable ZnMnO2 battery technologies with scales big enough to be considered for upscaling for industrial applications, are focused on the use of complicated synthesis of cathode materials and/or on the initial formation of the cathode material versus an auxiliary electrode, before being paired with a Zn electrode in a ZnMnO2 battery cell. These approaches, obviously, increase the complexity of the fabrication procedures and enhance the costs.
Making use of commercially available and ready materials, our MnO2 cathodes are simply synthesised via classical industrial-like processes and do not go through any in-situ synthesis or any initial formation versus a third electrode.
With a preliminary result of 800 cycles for 30% capacity fade (figure beside) on simple ZnMnO2 battery cells, several innovative experiments are planned and are on the way, to improve the cycle life.
RAMSES :
A bilateral French-German ANR project gathering ICMCB, ZSW, Hoppecke and Sunergy in a collaborative research work for demonstration of an innovative and low-cost rechargeable Zn-MnO2 battery technology at a TRL of 5 for stationary applications. By the end of the project, a battery prototype, will be constructed to fulfil requirements in terms of load profiles and costs for the energy storage from residential and grid photovoltaic production.