GS Yuasa's 5th Generation Flooded Lead-Acid Battery Technology for Stop and Start Vehicles

Transcription

1 GS Yuasa's 5th Generation Flooded Lead-Acid Battery Technology for Stop and Start Vehicles 7th Advanced Automotive Battery Conference Europe 2017 Satoshi Inagaki, Masaaki Kyo, Susumu Obuchi, Hidetoshi Wada, Taisuke Takeuchi, Tomohiro Imamura GS Yuasa International Ltd.

2 Outline 1 History of our EFB technology for Stop and Start 2 Market trend in Japan and failure modes in Stop and Start 3 Concept of 5th generation technology 4 Results of accelerated test and field operational test 5 Conclusion EFB:Enhanced Flooded lead-acid Battery

3 Outline 1 History of our EFB technology for Stop and Start 2 Market trend in Japan and failure modes in Stop and Start 3 Concept of 5th generation technology 4 Results of accelerated test and field operational test 5 Conclusion

4 History of EFB technology Objective Charge/discharge performance Durability Charge acceptance Technologies Generation 1st 2nd 3rd 4th 5th 2009~ 2010~ 2011~ 2012~ 2017~ Increased number of plates High density PAM Special additive in electrolyte Optimized additives in NAM with carbon technology : Improvement as compared with conventional batteries. : Additional improvement as compared with. : The new technology for the 5th generation

5 Outline 1 History of our EFB technology for Stop and Start 2 Market trend in Japan and failure modes in Stop and Start 3 Concept of 5th generation technology 4 Results of accelerated test and field operational test 5 Conclusion

6 Average monthly mileage / km Market trend in Japan Transition of user s average mileage Popularization of Stop and Start vehicles Year Reference) Japan automobile manufacturers association, Passenger Car Market Trends in Japan ( ) Users average mileage has been decreasing, because the main purpose of car users has been changing from leisure to daily or even weekly small business. Influence on batteries -Few charging opportunity -Prolonged non-operational time under PSoC

7 Failure modes in the field (1) Battery : M-42 (4th generation, C 20 =40Ah) Cars: 2 of different Japanese car manufacturers (shown as A and B) History: A [2218km/9.8months(226km/month)], B[2017km/9.3months(217km/month)] Car A Car B Grid corrosion Softening of PAM Short-circuits Sediment of dropped active material Shrinkage of NAM 5 Fatal degradation No degradation Dendrite formation Sulfation of NAM Change of separator color

8 Failure modes in the field (2) Battery : LN3 (4th generation, C 20 =70Ah) Cars: 1 of European car manufacturer s (shown as C) History: 30640km/22.2months(1378km/month) Car C Grid corrosion Softening of PAM Short-circuits Sediment of dropped active material Shrinkage of NAM Average mileage in Germany (2013) :1188km/month Dendrite formation Change of separator color Sulfation of NAM In the literature, sulfation of NAM under short mileage in Europe is also shown. S. Schaeck et al., Journal of Power Sources 196(2011) 2933 Sulfatuion of NAM should be common also in European market.

9 Description of sulfation SEM images of sulfated NAM In the Japanese car (short average mileage) In the European car (relatively long average mileage) Sulfation : Accumulation of highly crystallized lead sulfates (hard to recharge) Bad fuel efficiency and life performance due to the poor charge acceptance.

10 Outline 1 History of our EFB technology for Stop and Start 2 Market trend in Japan and failure modes in Stop and Start 3 Concept of 5th generation technology 4 Results of accelerated test and field operational test 5 Conclusion

11 Theoretical interpretation of sulfation Reactable Distance in charging process Isolated PbSO 4 Electrolyte Electrolyte Reactable Distance Pb 2+ PbSO 4 Pb 2+ Pb PbSO 4 Pb Initial stage Final stage References) Y. Arai et al., GS Yuasa Technical Report, 11(1),24(2014) Y. Arai et al., GS Yuasa Technical Report, 12(2),18(2015) Y. Arai, 9th International Conference On Lead-Acid Batteries(LABAT 2014) Isolated PbSO 4 should crystallize and go into sulfation during non-operational time. To reduce the isolated PbSO 4 by enhancing the Reactable Distance is important.

12 New carbon technology for 5th generation Features of the new carbon Carbon Particle Size Electron Conductivity Conventional Small Fair New Large Good PbSO 4 Conventional carbon particles (much smaller than PbSO 4 )

13 Strategy for improving sulfation Conventional carbon New carbon Large isolated PbSO 4 Small isolated PbSO 4 Electrolyte Electrolyte Short Reactable Distance PbSO 4 PbSO 4 Long Reactable Distance Pb Pb Carbons Conductive end Carbons With new carbon, the Reactable Distance should be enhanced by its large particle size and high electron conductivity so that only small isolated PbSO 4 will remain.

14 Outline 1 History of our EFB technology for Stop and Start 2 Market trend in Japan and failure modes in Stop and Start 3 Concept of 5th generation technology 4 Results of accelerated test and field operational test 5 Conclusion

15 Current / A Sulfation-accelerated battery test Battery : Test Profile : M-42 (5th and 4th generation, C 20 =40Ah) GS Yuasa original (simulating a short mileage use) Charge Max. 50A Temperature : V 90s 13.2V 12.85V 40s 80s Charge/Discharge balance in the test: Almost 100% Discharge 28A 50s 250A 0.5s Repeat 10 times Repeat 2 times 1 cycle 0.1A 2 h (rest time)

16 Voltage at the end of 250A discharge / V Sulfation-accelerated battery test Results th generation 4th generation x Cycles 5th 4th Sulfation was highly suppressed in the 5th generation battery.

17 Field operational test Battery :M-42 (5th and 4th generation, C 20 =40Ah) Cars : 1 of Japanese car manufacturer s (manufacturer A in the previous page) History: Same 2200km/10months(220km/month) for each battery Results Generation Before field driving test AC-IR / mω OCV / V After field driving test AC-IR / mω OCV / V 5 th th The same effect was confirmed in the real field

18 Water consumption / g Water Consumption in over charged test Battery : M-42 (5th and 4th generation, C 20 =40Ah) Test Profile : SAE J240 modified (25A for 1min. 14.8V/25A for 10min.at 75 ) th generation 4th generation Additional information Our 4th generation satisfies the W3 level defined in EN Temp. Voltage Duration Weight loss C 14.4V 42days 5.6g/Ah (<8) Cycles Battery :LN3 (4th generation, C 20 =70Ah) No bad influence with 5th generation technology

19 Outline 1 History of our EFB technology for Stop and Start 2 Market trend in Japan and failure modes in Stop and Start 3 Concept of 5th generation technology 4 Results of accelerated test and field operational test 5 Conclusion

20 Conclusion GS Yuasa s 5th generation battery with new carbon technology highly suppressed the sulfation of NAM in accelerated battery test and field operational test. Other findings Sulfation of NAM was the major failure mode in Japanese Stop and Start real market in which the users average mileage has been decreasing. The new technology has no bad influence on the water consumption. GS Yuasa s 5th generation battery is suitable for short-trip users.

21 Thank you for your attention.