Steatite has completed the first phase of a 24-month project to develop a pressure-tolerant lithium sulphur (Li-S) battery pack that can improve the endurance and speed of ‘deep-dive autonomous underwater vehicles (AUVs).
According to the company, after the demonstration that Li-S cells can operate at depths up to 6000 meters, the project can now move on to the battery development phase involving the development of Steatite’s pressure-tolerant multi-chemistry Battery Management System (BMS).
The first phase of the project was completed at the National Oceanography Centre (NOC) in Southampton and involved repeatedly testing Li-S cells at pressures and temperatures equivalent to undersea depths of 6,000 meters.
The results of the testing have demonstrated that the Li-S cells now deliver (almost) the same performance as at ambient conditions and that the effective Neutral Buoyancy Energy Density (NBED) is nearly double that of the Li-ion reference cells. Several cells have been used to perform life tests, and have now reached over 60 cycles for slow discharge, and 80 cycles of faster discharges, the company explained.
Paul Edwards , divisional director at Steatite Batteries, said: “The project is progressing well and successful completion of the cell development phase represents a significant milestone. We are now entering the battery development phase involving continued development of Steatite’s pressure-tolerant multi-chemistry Battery Management System (BMS). The system will be demonstrated in a deep-dive submarine in mid 2017.”