Liquid Reserve Fuze Batteries: Trying to Move Beyond The Status Quo. Jeff Swank US Army Research Laboratory

Transcription

1 Liquid Reserve Fuze Batteries: Trying to Move Beyond The Status Quo CREB Munitions Batteries Workshop 7 December 2016 Jeff Swank US Army Research Laboratory

2 Outline Some quick notes Technology and industrial base timeline Challenges encountered (technical and otherwise) Attempts to address those challenges Going Forward

3 Some Quick Notes This presentation focuses on liquid-electrolyte reserve batteries used in electronic fuzing applications (ARDEC, Picatinny Arsenal) Typically <10 watts required for up to 200 seconds, sustained output Typically require very fast rise times ( ms) over the entire operating temperature range Typically subjected to high rates (up to 18,000 RPM or more) of rotation Must survive significant launch accelerations Up to 30,000 G for large-caliber applications Up to 100,000 G for medium-caliber applications This presentation is not intended to address the much larger, more complex liquid reserves used in AMRDEC and MDA applications

4 Battery Examples Large caliber fuze battery (MOFA) AA Medium caliber fuze battery (XM80)

5 MOFA Cutaway Illustration Endplate Drive Disk Ball Seal Reservoir Case Cell Cup Spacer Cell Stack Electrolyte T.P. Insulator Cutter Cell Cup Bottom Positive Pin (GTM Seal) (+) Spring Terminal Plate (-) Interlock Pin (2 Places) Ground Pin (Case Ground) Multi-Option Fuze for Artillery (MOFA) battery 105- and 155-mm rifled artillery applications

6 Timeline: 1960s-Present Fuze batteries used lead/fluoboric acid/lead dioxide system from early 1960s until late 90s At one time, industrial base included EaglePicher, Eveready, Accudyne Army managed highly-specialized GOCO platers at the manu. facilities One by one, largely for business reasons, manufactures exited the business, the platers were dismantled, and we lost the capability to produce these batteries In the early 90s, the Government instituted acquisition reform and the Army reorganized its laboratory system The Army greatly reduced its organic capability in the area of fuze batteries The R&D burden was left almost entirely to the commercial sector Mitigating these events was the emergence of lithium-based battery systems in the mid- 80s, and the existence of ATK-Horsham, PA as a supplier ATK began working on multi-cell lithium-based reserve batteries in the mid-80s, at times with ARL participation In the early 90s, ATK began development of the first such fuze battery, the MOFA (Multi-Option Fuze for Artillery), which was produced from

7 Challenges Emerge Navy s MFF (Multi-Function Fuze) battery development Beginning around 1999, the Navy made two attempts to modify the MOFA battery design to meet the requirements of the MFF fuze Higher voltage and greater current draw (added cells but had a fixed electrode area) Full power required much earlier in MFF than MOFA Neither attempt was fully successful; primary issue was rise time Submunitions and medium-caliber (25-40 mm projectile) applications Beginning in the late 1990s, efforts began to add electronic fuzing to a number of new applications that would require much smaller batteries esdf, OICW, XM80, ANLM, LW30, SAGM Most of the new applications included a proximity function, requiring 10s of ma Medium-caliber applications are typically short mission lives, but require very fast rise times ( ms) Success has been hard to come by The batteries need to be really small Programs come and go, making it hard to gain traction Nature of the electrochemistry extremely limits materials of construction Cold temperature rise time continues to be an issue But, efforts persist, because we want the capability

8 Where Things Stand The industrial base for fuze batteries is very small EnerSys has been the only committed producer for the last 20 years The Army has not had a fuze battery in high-rate production since 2007 Financial stress on the existing base No incentive to expand base Harder to argue for significant R&D investment Organic Government capability remains very limited DoD-unique; no opportunities to leverage commercial activities The Government community has investigated alternative technologies 1995 report by NSWC-Carderock (focused on large-caliber solutions) 2002 report by Rensselaer Polytechnic Institute (ARDEC-commissioned) The fuze community has also considered alternative electrochemical systems in reserve configuration, as well as primary and secondary batteries

9 Alternatives Considered NSWC Spring Turbine alternator Flywheel generator Gear train (runaway) Gear train (escapement) Setback generator Piezo-stress Piezo-crush Fluidic generator Thermoelectric converter Gas generator Thermo-photovoltaic converter Thermionic converter Driven mainspring/generator Photoemissive converter Ferroelectric converter Magnetohydrodynamic converter Refrigerated thermoelectric converter Negator spring motor generator RPI Supercapacitors Micro power generation (MEMS) Thermoelectrics Photovoltaics Piezoelectrics Radio isotope batteries Fuel cells Superconducting magnets Thermophotovoltaics Conformal systems

10 Going Forward, Near Term Ongoing fuze programs will continue to pursue lithium-based reserve batteries, expanding the design and performance envelopes incrementally ARDEC beginning aging study of select primary and secondary COTS batteries May investigate reserve configurations with alternative electrochemical systems, at least for certain applications (i.e., fast rise time vs. higher energy density), resources permitting