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US5481174A
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Method of rapidly charging a lithium ion cell
Assignee: Motorola Mobility LLC
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Filing: 1993-12-27
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Granted: 1996-01-02
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Expires: 2013-12-27
Abstract
Abstract A battery charger for lithium ion cells closely monitors cell voltage, and charge time, so as to avoid the over-application of charge to the cell. Charge pulses (104) are followed by a first rest (110), a discharge (112) and a second rest, (120) period prior to re-initiating the charge pulse. If the battery voltage reaches a preselected maximum, in less than a pre-selected period of time, the charge pulse is reduced by a preselected minimum factor. Cycling of the cell is continued until the cells are fully charged.
Inventors
- 👤 Lara J. Martin
- 👤 Scott M. Garrett
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:49
CPC Classifications
H; H02; H02J; H02J7/00; H02J7/90; H02J7/927
Claims Analysis
Total Claims: 17
Claim 1
Independent Claim
101 words
A method for rapidly charging a Lithium ion electrochemical cell, said method comprising the steps of: (i) providing a Lithium ion electrochemical cell; (ii) applying an electrical charge pulse current to said electrochemical cell, said charge pulse terminating upon the occurrence of either a pre-selected maximum charge time, or a pre-selected maximum cell voltage; (iii) providing a rest period during which no load or current is applied to said cell; and (iv) applying a discharge pulse to said electrochemical cell, said discharge pulse terminating upon the occurrence of either a pre-selected discharge period of time, or a pre-selected minimum cell voltage.
Claim 2
Independent Claim
101 words
A method for rapidly charging a Lithium ion electrochemical cell, said method comprising the steps of: (i) providing a Lithium ion electrochemical cell; (ii) applying an electrical charge pulse current to said electrochemical cell, said charge pulse terminating upon the occurrence of either a pre-selected maximum charge time, or a pre-selected maximum cell voltage; (iii) providing a rest period during which no load or current is applied to said cell; and (iv) applying a discharge pulse to said electrochemical cell, said discharge pulse terminating upon the occurrence of either a pre-selected discharge period of time, or a pre-selected minimum cell voltage.
Claim 3
Dependent Claim
22 words
A method as described in claim 1, including the further step of providing a second rest period after applying said discharge pulse.
Claim 4
Dependent Claim
19 words
A method as described in claim 2, including the further step of repeating said charge, rest, and discharge steps.
Claim 5
Dependent Claim
33 words
A method as described in claim 3, including the further step of decreasing the charge pulse current when said pre-selected maximum cell voltage is reached in less than a pre-selected minimum charge time.
Claim 6
Dependent Claim
41 words
A method as described in claim 4, including the further step of charging said electrochemical cell until a pre-selected minimum charge pulse current causes said cell to reach said pre-selected maximum cell voltage in less than said pre-selected minimum charge time.
Claim 7
Dependent Claim
15 words
A method as described in claim 1, wherein the initial charge pulse current is 2C.
Claim 8
Dependent Claim
20 words
A method as described in claim 2, wherein one charge-rest-discharge-rest cycle has a duration of between 10 and 60 seconds.
Claim 9
Dependent Claim
23 words
A method as described in claim 7, wherein said pre-selected maximum charge time is at least about 80% of the total charge-rest-discharge-rest cycle.
Claim 10
Dependent Claim
16 words
A method as described in claim 1, wherein said pre-selected maximum cell voltage is 4.2 volts.
Claim 11
Dependent Claim
20 words
A method as described in claim 2, wherein the duration of the discharge pulse is between 0.5 and 5.0 seconds.
Claim 12
Dependent Claim
35 words
A method as described in claim 4, wherein the charge pulse current is reduced by a factor of 1/2 when said pre-selected maximum cell voltage is reached in less than the pre-selected minimum charge time.
Claim 13
Dependent Claim
16 words
A method as described in claim 1, wherein said pre-selected minimum cell voltage is 2.5 V.
Claim 14
Independent Claim
126 words
A method for rapidly charging a lithium ion electrochemical cell, said method comprising the steps of: providing a lithium ion electrochemical cell; applying an electrical charge pulse current to said electrochemical cell, said charge pulse terminating upon the occurrence of either a pre-selected maximum charge time, or a pre-selected maximum cell voltage; providing a first rest period during which no load or current is applied to said cell; applying a discharge pulse to said electrochemical cell said discharge pulse terminating upon the occurrence of either a pre-selected minimum cell voltage, or a pre-selected discharge period of time; and providing a second rest period during which no load or current supply to said cell; and repeating said charge-rest-discharge-rest cycle until said electrochemical cell is substantially completely charged.
Claim 15
Independent Claim
126 words
A method for rapidly charging a lithium ion electrochemical cell, said method comprising the steps of: providing a lithium ion electrochemical cell; applying an electrical charge pulse current to said electrochemical cell, said charge pulse terminating upon the occurrence of either a pre-selected maximum charge time, or a pre-selected maximum cell voltage; providing a first rest period during which no load or current is applied to said cell; applying a discharge pulse to said electrochemical cell said discharge pulse terminating upon the occurrence of either a pre-selected minimum cell voltage, or a pre-selected discharge period of time; and providing a second rest period during which no load or current supply to said cell; and repeating said charge-rest-discharge-rest cycle until said electrochemical cell is substantially completely charged.
Claim 16
Dependent Claim
33 words
A method as described in claim 13 including the further step of decreasing the charge pulse current when said pre-selected maximum cell voltage is reached in less than a pre-selected minimum charge time.
Claim 17
Dependent Claim
41 words
A method as described in claim 14, including the further step of charging said electrochemical cell until a pre-selected minimum charge pulse current causes said cell to reach said pre-selected maximum cell voltage in less than said pre-selected minimum charge time.
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| 7.5 Years (Year 8) | 2003-01-01 | 2003-07-03 | 2004-01-02 | $3760.00 | Window Closed / Lapsed |
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