Green Science Alliance Develops Stable Aqueous Aluminum-Ion Battery with Carbon Rubber Current Collector

Green Science Alliance has announced a stable rechargeable aqueous aluminum-ion battery (AAIB) that uses a cheap conductive carbon rubber sheet as the cathode current collector. This design avoids the corrosive and moisture-sensitive ionic liquid electrolytes used in other aluminum batteries, enabling manufacturing under normal conditions. The battery shows an initial capacity of at least 210 mAh/g at 0.025 C, maintained for 25 cycles, with testing still ongoing. The porous carbon rubber sheet creates a 3D structure that improves performance and eliminates the need for expensive corrosion-resistant metals. The battery uses graphite as the cathode, a paper separator, and an aqueous aluminum perchlorate electrolyte. The company projects costs could drop to $55-60 per kWh at scale, compared to roughly $115 for lithium-ion batteries. While the voltage is lower (0.9-1.0 V), it can be addressed by connecting cells in series. The results will be presented at the 250th ECS Meeting in October 2026, and further work aims to improve capacity and cycle stability.