US 9,812,741 B2
Method of charging and maintaining lithium ion secondary battery, battery system, vehicle and battery-mounted device
Takeshi Abe, Okazaki (JP); Akira Tsujiko, Miyoshi (JP); Tomitaro Hara, Okazaki (JP); Keiko Wasada, Toyota (JP); and Sachie Yuasa, Okazaki (JP)
Assigned to Toyota Jidosha Kabushiki Kaisha, Toyota-shi, Aichi (JP)
Appl. No. 13/264,800
Filed by Takeshi Abe, Okazaki (JP); Akira Tsujiko, Miyoshi (JP); Tomitaro Hara, Okazaki (JP); Keiko Wasada, Toyota (JP); and Sachie Yuasa, Okazaki (JP)
PCT Filed Apr. 28, 2009, PCT No. PCT/JP2009/058378
§ 371(c)(1), (2), (4) Date Dec. 6, 2011,
PCT Pub. No. WO2010/125649, PCT Pub. Date Nov. 4, 2010.
Prior Publication US 2012/0068666 A1, Mar. 22, 2012
Int. Cl. H02J 7/00 (2006.01); H01M 10/44 (2006.01); H01M 4/58 (2010.01); H01M 10/0525 (2010.01)
CPC H01M 10/44 (2013.01) [H02J 7/0075 (2013.01); H01M 4/5825 (2013.01); H01M 10/0525 (2013.01); Y02E 60/122 (2013.01)] 11 Claims
OG exemplary drawing
 
1. A method of charging and maintaining at least one of lithium ion secondary batteries, each using positive active material particles in its positive electrode plate, the positive active material particles being made from a two-phase coexistence type positive active material in which a first phase including Li ions inserted therein and a second phase from which Li ions have been desorbed coexist, the method comprising:
an overcharge step for simultaneously charging all of the at least one of the lithium ion secondary batteries to an overcharge SOC (state of charge) that is not higher than 100% SOC but higher than a target SOC;
a return discharge step for simultaneously discharging, after the overcharge step, all of the at least one of the lithium ion secondary batteries to make the SOC of all of the at least one of the batteries equal to the target SOC and make outermost peripheries of the positive active material particles be the first phase; and
a maintaining step for simultaneously maintaining, following the return discharge step, the SOC of all of the at least one of the lithium ion secondary batteries at the target SOC until next discharge of all of the at least one of the lithium ion secondary batteries is started, wherein the maintaining step includes maintaining the target SOC without increasing and decreasing the SOC of all of the at least one of the lithium ion secondary batteries.