In Submarine Matters'ongoing examination of Lithium-ion Batteries (LIBs) Anonymous's research and comments are always helpful. Anonymous's comments of September 16 to 27, 2017 reveal much about the likely choice, management and operation of LIBs on submarines. Japan is leading the way with LIBs - planning full conversion to LIBs on new submarines launched from 2018 onwards (see Table below).
1 Oyashio class (built 1994-2006, see Table below)
In the eleven Oyashio class subs are classic DC motors reliant on limited capacity LABs. These make the sub's fully submerged speed control complex. LABs are in 2 identical sections fore and aft (ie. 4 identical sections overall)
M/O of LABs are in parallel or series connection in sections/subsections
Propulsion: 2 identical DC motors
2 Soryu MK 1's (built 2005-present)
In the ten Soryu Mk 1s, latest Permanent Magnet Synchronous Motors (PMSMs) make speed control of the submarine easier. But the management of two power supply systems (LABs & AIP) is complex.
LABs: fore and aft sections consisted of 2 identical subsections, respectively (ie. 4 identical sections overall)
Stirling AIP
M/O of LABs: unknown
Propulsion: smaller and bigger AC motors; smaller one is for low speed
3 Soryu Mk 2s (estimation)(built 2015 (see Table) perhaps through to 2018)
Soryu Mk 2s adopt the simplest M/O system among Japanese submarines.
LIBs: fore and aft sections will consist of 2 identical subsections, respectively (ie. 4 identical sections overall)
M/O of LIBs: unknown, but may be in 4 phases, see i) to iv) above.
Propulsion: 2 identical AC motors
TABLE - SORYU & Oyashio Program as at October 3, 2017
In the development of new LIB materials and control equipment for Japan's latest Soryu submarines, rigorous testing, prior to operational use, is required. LIB materials and equipment may fail under accelerated and severe condition testing. This includes testing under:
- high or very low temperatures (the operational temperature of LIBs on Japanese submarines is
within the range of 10-45 degrees C for efficient and safe operation)
within the range of 10-45 degrees C for efficient and safe operation)
- high pressures
- strong mechanical stress, and
- continuous vibration testing, etc.
Tri-ring advised the two simplest ways to avoid the particular LIB problem of "lithium plating" is to:
- prevent over voltage during charging of LIBs (above 4.2 volts per cell), and
- charging and discharging at low temperature (below 15⁰C).
He adds that to counter thermal runaway of LIBs, great advances have been made in material science. One of them is a ceramic separator that has much higher resistance against heat.
The Japanese Ministry of Defence's (MOD) Acquisition, Technology & Logistic Agency (ATLA) and the Japanese Navy have been (and will be) conducting such testing of LIBs. For more accurate establishment of LIB safety standards, non accelerated testing under normal condition is preferable, even if this is time-consuming.
Choice of LIBs
Choice of LIBs
Japan has explored submarine use of many LIB combinations, including two that show exceptional stability at low temperatures and long charge-discharge cycle lives. These are :
- Lithium Iron Phosphate (LFP) 2,000 cycle lives, and - Lithium Titanate (LTO) ( Li4Ti5O12 ) 7,000 cycles, made by Toshiba.
For LEP and LTO such stability at low temperatures and long cycle lives comes at the cost of low energy density.
Drawing from this article. To remedy this low LIB energy density problem Japan may well have settled on Lithium nickel cobalt aluminium oxide (NCA), ( LiNiCoAlO2 ) LIBs for its Navy. These LIBs are made by GS Yuasa. Such LIBs are ideal for the Japanese Navy's mid-range continuous patrol operations.
Drawing from this article. To remedy this low LIB energy density problem Japan may well have settled on Lithium nickel cobalt aluminium oxide (NCA), ( LiNiCoAlO2 ) LIBs for its Navy. These LIBs are made by GS Yuasa. Such LIBs are ideal for the Japanese Navy's mid-range continuous patrol operations.
All this LIB testing and subsequent use on Soryu submarines via liaison with France's Naval Group may contribute to use of LIBs on Australia's Shortfin Future Submarines (FSM). LIBs on Shortfins may be added from the first Shortfins onwards or fitted to later build Shortfins. TKMS, Saab-Kockums, Naval Group, Russia, China and MHI/KHI may develop fundamentally different LIBs for other submarines. Also their differing diesel engines are an additional diesel-electric variable. This means the efficiency and safety of LIBs developed by one submarine builder may note ensure efficient and safe use by other builders.
For example Saab-Kockums and Russia that build submarines mainly for cold water operations may prefer LFP LIBs that may be more efficient in icy temperatures. As a customer Canada may prefer low temperature LIBs for its near Arctic Ocean operations.
LIBs Management and Operation
For example Saab-Kockums and Russia that build submarines mainly for cold water operations may prefer LFP LIBs that may be more efficient in icy temperatures. As a customer Canada may prefer low temperature LIBs for its near Arctic Ocean operations.
LIBs Management and Operation
Anonymous does not think a submarine's LIBs are discharged homogeneously (all at once and evenly). The numbers of charges and discharges of LIBs during (say) a total of 4 charge-discharge phases over 96 hours) might occur as follows:
i) half of the LIBs in the forward battery section may be used for the sub's first fully submerged dive and then charged in the first snorting,
ii) the other half of the forward LIBs is used for the second dive, then charged in the second snorting phase
iii) half of the LIBs in aft battery section is used for the third dive and then charged in the third snorting, and
iv) the another half of the LIBs in the aft battery section is used for the fourth dive and then charged in the fourth snorting.
The management/operation (M/O) system of batteries/propulsion of Japanese Oyashio and Soryu submarines is shown in 1 to 3 below.
i) half of the LIBs in the forward battery section may be used for the sub's first fully submerged dive and then charged in the first snorting,
ii) the other half of the forward LIBs is used for the second dive, then charged in the second snorting phase
iii) half of the LIBs in aft battery section is used for the third dive and then charged in the third snorting, and
iv) the another half of the LIBs in the aft battery section is used for the fourth dive and then charged in the fourth snorting.
The management/operation (M/O) system of batteries/propulsion of Japanese Oyashio and Soryu submarines is shown in 1 to 3 below.
1 Oyashio class (built 1994-2006, see Table below)
In the eleven Oyashio class subs are classic DC motors reliant on limited capacity LABs. These make the sub's fully submerged speed control complex. LABs are in 2 identical sections fore and aft (ie. 4 identical sections overall)
M/O of LABs are in parallel or series connection in sections/subsections
Propulsion: 2 identical DC motors
2 Soryu MK 1's (built 2005-present)
In the ten Soryu Mk 1s, latest Permanent Magnet Synchronous Motors (PMSMs) make speed control of the submarine easier. But the management of two power supply systems (LABs & AIP) is complex.
LABs: fore and aft sections consisted of 2 identical subsections, respectively (ie. 4 identical sections overall)
Stirling AIP
M/O of LABs: unknown
Propulsion: smaller and bigger AC motors; smaller one is for low speed
3 Soryu Mk 2s (estimation)(built 2015 (see Table) perhaps through to 2018)
Soryu Mk 2s adopt the simplest M/O system among Japanese submarines.
LIBs: fore and aft sections will consist of 2 identical subsections, respectively (ie. 4 identical sections overall)
M/O of LIBs: unknown, but may be in 4 phases, see i) to iv) above.
Propulsion: 2 identical AC motors
SS No. | Build No Name | Pennant No. | MoF approved amount ¥ Billions FY | LABs, LIBs, AIP | Laid Down | Laun -ched | Commi ssioned | Built By |
5SS Oyashio | 8105 Oyashio | SS-590/ TS3608 | ¥52.2B FY1993 | LABs only | Jan 1994 | Oct 1996 | Mar 1998 | KHI |
6SS-15SS Oyashios 10 subs | 8106 -8115 various | SS-591-600 | ¥52.2B per sub FY1994-FY2003 | LABs only | 15SS Feb 2004 | 15SS Nov 2006 | 15SS Mar 2008 | MHI & KHI |
16SS Soryu Mk 1 | 8116 Sōryū | SS-501 | ¥60B FY2004 | LABs + AIP | Mar 2005 | Dec 2007 | Mar 2009 | MHI |
17SS | 8117 Unryū | SS-502 | ¥58.7B FY2005 | LABs + AIP | Mar 2006 | Oct 2008 | Mar 2010 | KHI |
18SS | 8118 Hakuryū | SS-503 | ¥56.2 FY2006 | LABs + AIP | Feb 2007 | Oct 2009 | Mar 2011 | MHI |
19SS | 8119 Kenryū | SS-504 | ¥53B FY2007 | LABs + AIP | Mar 2008 | Nov 2010 | Mar 2012 | KHI |
20SS | 8120 Zuiryū | SS-505 | ¥51B FY2008 | LABs + AIP | Mar 2009 | Oct 2011 | Mar 2013 | MHI |
No 21SS | No 21SS built | |||||||
22SS | 8121 Kokuryū | SS-506 | ¥52.8B FY2010 | LABs + AIP | Jan 2011 | Oct 2013 | Mar 2015 | KHI |
23SS | 8122 Jinryu | SS-507 | ¥54.6B FY2011 | LABs + AIP | Feb 2012 | Oct 2014 | 7 Mar 2016 | MHI |
24SS | 8123 Sekiryū | SS-508 | ¥54.7B FY2012 | LABs + AIP | KHI | |||
25SS | 8124 | SS-509 | ¥53.1B FY2013 | LABs + AIP | 22 Oct 2013 | 12 Oct 2016 | Mar? 2018 | MHI |
26SS | 8125 | SS-510 | LABs + AIP | 2014 | ? | Mar 2019? | KHI | |
27SS First Soryu Mk 2 | 8126 | SS-511 | LIBs only | 2015 | 2017? | Mar 2020 | MHI | |
28SS Second Soryu Mark 2 | 8127 | SS-512 | ¥63.6B FY2016 | LIBs only | 2016? | 2018? | Mar 2021? | KHI |
29SS First Soryu Mk 3 | 8128 | ? | ¥76B FY2017 | LIBs only | ? | ? | 2023? | MHI? |
30SS Second Soryu Mk 3 | 8029? | ? | ¥71.5B FY2018 | LIBs only | ? | ? | 2024? | KHI? |
Table from information exclusively provided to Submarine Matters. LABs = lead-acid batteries, AIP = air independent propulsion, LIBs = lithium-ion batteries. ¥***B = Billion Yen. MHI = Mitsubishi Heavy Industries, KHI = Kawasaki Shipbuilding Corporation of Kawasaki Heavy Industries.
---So LIB Management and Operation is complex but as the batteries work to computer terminals a submarine's engineers should be able to manage and operate LIBs more easily than lead-acid batteries.
Pete