PULSE BATTERY CHARGER METHODS AND SYSTEMS FOR IMPROVED CHARGING OF LITHIUM ION BATTERIES

• US 20140266068A1
• Filed: 03/13/2014
• Published: 09/18/2014
• Est. Priority Date: 03/14/2013
• Status: Abandoned Application

• Current Assignee: Evgentech, Inc.
• Original Assignee: Evgentech, Inc.
• Inventors: Hung, Stephen T., O'Brien, Timothy J., Thomas, George
• Application Number:
  US14/210,101
• Publication Number:
  US 20140266068A1
• Time in Patent Office: Days
• US Class Current: 320/139
• CPC Class Codes: B60L 2240/545 Temperature
• CPC Class Codes: B60L 2240/547 Voltage
• CPC Class Codes: B60L 2240/549 Current
• CPC Class Codes: B60L 2240/80 Time limits
• CPC Class Codes: B60L 2260/44 by parameter estimation
• CPC Class Codes: B60L 3/003 relating to inverters
• CPC Class Codes: B60L 3/0046 relating to electric energy storage systems, e.g. batteries or capacitors
• CPC Class Codes: B60L 3/04 Cutting off the power supply under fault conditions protective devices and circuit arrangements in general H01H; H02H
• CPC Class Codes: B60L 50/16 with provision for separate direct mechanical propulsion
• CPC Class Codes: B60L 50/64 Constructional details of batteries specially adapted for electric vehicles
• CPC Class Codes: B60L 53/11 DC charging controlled by the charging station, e.g. mode 4
• CPC Class Codes: B60L 53/14 Conductive energy transfer
• CPC Class Codes: B60L 58/12 responding to state of charge [SoC]
• CPC Class Codes: B60L 58/21 having the same nominal voltage
• CPC Class Codes: B60L 7/12 for vehicles propelled by dc motors
• CPC Class Codes: H02J 2310/48 for electric vehicles [EV] or hybrid vehicles [HEV]
• CPC Class Codes: H02J 7/00711 with introduction of pulses during the charging process
• CPC Class Codes: H02J 7/00714 in response to battery charging or discharging current
• CPC Class Codes: H02J 7/007182 in response to battery voltage
• CPC Class Codes: Y02T 10/70 Energy storage systems for electromobility, e.g. batteries
• CPC Class Codes: Y02T 10/7072 : Electromobility specific charging systems or methods for batteries, ultracapacitors, supercapacitors or double-layer capacitors
• CPC Class Codes: Y02T 90/12 : Electric charging stations
• CPC Class Codes: Y02T 90/14 : Plug-in electric vehicles

Abstract

The inventions herein relate to devices and methods to impart charge to lithium ion battery cells. Still further, the present invention incorporates to pulse charging methods and systems related thereto that provide improvements in charging speed, efficiency and additional benefits.

Claims

1. A process for charging a Li-ion battery cell, wherein the process comprises:

a) providing at least one Li-ion battery cell, wherein the battery cell comprises;

i) a series internal resistance (R_s);

ii) a maximum acceptable battery terminal voltage (V_max);

iii) a battery terminal voltage (V_Batt); and

iv) an instantaneous open circuit voltage (OCV_inst);

b) applying to the battery cell a plurality of charging pulses to provide a desired C rate,

i) wherein each charging pulse, independently, comprises an ON-time and an OFF-time, wherein the ON-time follows the OFF-time,

ii) wherein the process during the OFF-time presents to the battery the nature of an open circuit, and

iii) wherein the battery terminal voltage, V_Batt, during the ON-time portion of each of the plurality of voltage pulses, independently, is determined according to the formula;

V_Batt=I_Batt×

R_s+OCV_inst

and

I_Batt=I_BattCavg×

(pulse period)/(on-time duration);

where I_BattCavg comprises the C rate applied to the battery.

2. The method of claim 1, wherein the plurality of charging pulses is applied to Li-ion battery cell to provide at least about 95% SOC and wherein OCV_inst substantially does not exceed V_max during application of substantially of the plurality of charging pulses.

3. The method of claim 1, wherein I_BattCavg is at least about 1 C, wherein the battery cell SOC is at least about 95% or more in about 60 minutes or less.

4. The method of claim 1, wherein I_BattCavg is at least about 1.5 C, wherein the battery cell SOC is at least about 95% or more in about 30 minutes or less.

5. The method of claim 1, wherein OCV_inst determined by one or more of:

a. sampling one or more times during a trough occurring during each OFF-time; and

b. estimating from measurement of battery terminal voltage during application of the plurality of charging pulses.