Pressure vessels, nickel-hydrogen batterie

J. Zagrodnik and K. Jones, Development of Common Pressure Vessel Nickel-Hydrogen Batteries, Pwc. 25th lECEC, 1990. 

The present state of development of individual pressure vessel (IPV) nickel-hydrogen battery cells is that they are acceptable where not many cycles are required over life, i.e. 1000 cycles over 10 years of geosynchronous orbit applications, but are not acceptable in applications where many cycles are required, typically 30 000 over five years. In low earth orbit applications only 6000 to 10000 cycles at 80% depth of discharge can be achieved. 

The cell or battery is enclosed in a stainless steel or Inconel pressure vessel (Fig. 9.23). Hydrogen pressure rises from about 0.5 MPa in the fully discharged state to 3-10 MPa when charged, and the pressure in the vessel can be used to monitor the state of charge. Direct reaction between hydrogen and nickel oxide is relatively slow, but 6-12% of capacity is lost per day. 

A low-cost nickel-hydrogen system proposed by Eagle Picher is based on the multiple cell per single battery pressure vessel concept. Additional system cost reduction is proposed through use of standardized components, ease of manufacture and an inherent design versatility able to meet various voltage and capacity requirements with only minor modifications. 

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