Charging condition control apparatus and battery pack

• US 10,193,195 B2
• Filed: 09/09/2016
• Issued: 01/29/2019
• Est. Priority Date: 09/09/2015
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Morita, Tomokazu, Kuboki, Takashi, Matsuno, Shinsuke
• Primary Examiner(s): Williams, Arun C
• Application Number:
  US15/260,614
• Publication Number:
  US 20170069938A1
• Time in Patent Office: 872 Days
• Field of Search: 320112
• CPC Class Codes: H01M 10/0525 Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
• CPC Class Codes: H01M 10/446 Initial charging measures
• CPC Class Codes: H01M 10/448 End of discharge regulating measures
• CPC Class Codes: H01M 10/46 Accumulators structurally combined with charging apparatus circuits for charging H02J7/00
• CPC Class Codes: H01M 10/48 Accumulators combined with arrangements for measuring, testing or indicating the condition of cells, e.g. the level or density of the electrolyte constructional details of current conducting connections for detecting conditions inside cells or batteries, e.g. details of voltage sensing terminals, H01M50/569
• CPC Class Codes: H01M 4/386 Silicon or alloys based on silicon
• CPC Class Codes: H01M 4/587 for inserting or intercalating light metals
• CPC Class Codes: H02J 7/0048 Detection of remaining charge capacity or state of charge [SOC]
• CPC Class Codes: H02J 7/007 Regulation of charging or discharging current or voltage
• CPC Class Codes: H02J 7/04 Regulation of charging current or voltage
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

According to an embodiment, a charging condition control apparatus includes a measurement unit, an estimation unit, a calculation unit and a control unit. The measurement unit measures a present battery capacity of a secondary battery. The estimation unit estimates a present end-of-charge potential of an anode of the secondary battery based on the present battery capacity and an open circuit potential curve of the anode. The calculation unit calculates a differential potential between the present end-of-charge potential and an initial end-of-charge potential of the anode. The control unit controls a charging condition of the secondary battery according to the differential potential.

Claims

1. A charging condition control apparatus, comprising:

a measurement unit configured to measure a present battery capacity of a secondary battery;

an estimation unit configured to estimate a present end-of-charge potential of an anode of the secondary battery based on the present battery capacity and an open circuit potential curve of the anode;

a calculation unit configured to calculate a differential potential between the present end-of-charge potential and an initial end-of-charge potential of the anode; and

a control unit configured to control a charging condition of the secondary battery according to the differential potential,

wherein the estimation unit estimates the present end-of-charge potential by calculating a depth of charge of the anode based on the present battery capacity and an initial battery capacity and by retrieving a potential corresponding to the depth of charge from the open circuit potential curve.

2. The apparatus according to claim 1, wherein the control unit derives an end-of-charge voltage of the secondary battery by subtracting the differential potential from an initial end-of-charge voltage of the secondary battery.

3. A battery pack, comprising:

a secondary battery that comprises a cathode and an anode;

a measurement unit configured to measure a present battery capacity of the secondary battery;

an estimation unit configured to estimate a present end-of-charge potential of the anode based on the present battery capacity and an open circuit potential curve of the anode;

a calculation unit configured to calculate a differential potential between the present end-of-charge potential and an initial end-of-charge potential of the anode;

a control unit configured to control a charging condition of the secondary battery according to the differential potential; and

a charger that charges the secondary battery according to the charging condition,

wherein the estimation unit estimates the present end-of-charge potential by calculating a depth of charge of the anode based on the present battery capacity and an initial battery capacity and by retrieving a potential corresponding to the depth of charge from the open circuit potential curve.

4. The battery pack according to claim 3, wherein the anode comprises silicon and a carbon-based material that absorb lithium.