	US RE50,521 E1
	Lithium secondary battery pack, as well as electronic device, charging system, and charging method using said pack
Haruki Kamizori, Kyoto (JP); Masayuki Yamada, Kyoto (JP); and Fusaji Kita, Kyoto (JP)
Assigned to MAXELL, LTD., Kyoto (JP)
Appl. No. 18/088,334
Filed by Maxell, Ltd., Kyoto (JP)
PCT Filed Feb. 25, 2014, PCT No. PCT/JP2014/054537 § 371(c)(1), (2) Date Sep. 1, 2015, PCT Pub. No. WO2014/141875, PCT Pub. Date Sep. 18, 2014.
Application 18/088,334 is a continuation of application No. 16/987,159, filed on Aug. 6, 2020, granted, now RE49407.
Application 18/088,334 is a reissue of application No. 14/772,043, filed on Feb. 25, 2014, granted, now 10,044,072, issued on Aug. 7, 2018.
Claims priority of application No. 2013-048298 (JP), filed on Mar. 11, 2013.
This patent is subject to a terminal disclaimer.
Int. Cl. H01M 10/0525 (2010.01); H01M 4/38 (2006.01); H01M 4/48 (2010.01); H01M 4/587 (2010.01); H01M 10/052 (2010.01); H01M 10/0585 (2010.01); H01M 10/42 (2006.01); H01M 10/44 (2006.01); H01M 10/46 (2006.01); H01M 10/637 (2014.01); H01M 50/209 (2021.01); H02J 7/00 (2006.01)

CPC H01M 10/0525 (2013.01) [H01M 4/386 (2013.01); H01M 4/48 (2013.01); H01M 4/483 (2013.01); H01M 4/587 (2013.01); H01M 10/052 (2013.01); H01M 10/0585 (2013.01); H01M 10/425 (2013.01); H01M 10/441 (2013.01); H01M 10/46 (2013.01); H01M 10/637 (2015.04); H01M 50/209 (2021.01); H02J 7/00 (2013.01); H02J 7/0013 (2013.01); H01M 2010/4271 (2013.01); H01M 2200/106 (2013.01); H01M 2200/30 (2013.01); Y02E 60/10 (2013.01); Y02P 70/50 (2015.11); Y02T 10/70 (2013.01)]

20 Claims

1. A lithium secondary battery pack comprising:

a lithium secondary battery comprising ~~an electrode body formed of~~ a positive electrode and a negative electrode ~~facing each other and a separator interposed therebetween, and a non-aqueous electrolyte; a PTC element;~~ [ ; ] and a protection circuit ~~comprising a field effect transistor,~~ [ ,]

wherein the negative electrode ~~comprises a negative electrode material mixture layer that~~ contains an Si-containing material as a negative electrode active material,

the lithium secondary battery has an energy density per volume of 450 Wh/L or more,

the lithium secondary battery has a current density of 3.0 mA/cm²or less, and

a relational expression (1) and a relational expression (2) below are established where A (mΩ) is an impedance of the lithium secondary battery, B (mΩ) is an impedance of an entire circuit unit of the lithium secondary battery pack excepting the impedance A (mΩ) of the lithium secondary battery, and the impedance B (mΩ) is determined by subtracting the impedance A (mΩ) from the impedance of the entire circuit unit of the lithium secondary battery pack:

A≤50 mΩ (1)

B/A≤1 (2).