Patent Publication Number: US-2023155213-A1

Title: Bipolar capacitor assisted battery

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of Chinese Patent Application No. 202111338571.2, filed on Nov. 12, 2021. The entire disclosure of the application referenced above is incorporated herein by reference. 
     INTRODUCTION 
     The information provided in this section is for the purpose of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure. 
     The present disclosure relates to batteries and more particularly to capacitor assisted batteries. 
     Hybrid and electric vehicles include one or more motors that are powered by a battery system and that propel the vehicle. The battery system can be recharged using utility power, by another vehicle, during regeneration and/or by an internal combustion engine (for hybrid vehicle applications). During operation of the hybrid and/or electric vehicle, power that is generated during braking of the vehicle may be used to recharge a battery system of the vehicle. Instead of braking the vehicle using mechanical brakes, the motor is operated as a generator to brake the vehicle and to generate power that is used to recharge the battery system. 
     SUMMARY 
     A bipolar capacitor assisted battery includes a bipolar capacitor including a first capacitor and a second capacitor. The second capacitor is connected in series with the first capacitor. A lithium ion battery is connected in parallel to the bipolar capacitor. 
     In other features, the bipolar capacitor includes a first positive terminal. The first capacitor includes a first capacitor electrode connected to the first positive terminal. A first separator is connected to the first capacitor electrode. A first anode is connected to the first separator. A current collector is connected to the first anode. The second capacitor comprises a second capacitor electrode connected to the current collector, a second separator connected to the second capacitor electrode, and a second anode. A first negative terminal is connected to the second anode. 
     In other features, the lithium ion battery comprises a third anode connected to the first negative terminal, a third separator connected to the third anode and a first cathode connected to the third separator. A second positive terminal is connected to the first cathode. A second cathode is connected to the second positive terminal. A fourth separator is connected to the second anode. A fourth anode is connected to the fourth separator. A second negative terminal is connected to the fourth anode. A fifth anode is connected to the second negative terminal. A fifth separator is connected to the fifth anode. A third cathode is connected to the fifth separator. A third positive terminal is connected to the third cathode. A fourth cathode is connected to the third positive terminal. A sixth separator is connected to the fourth cathode. A sixth anode is connected to the sixth separator. 
     In other features, a blocking material is arranged on at least the first separator of the first capacitor and the second separator of the second capacitor. The bipolar capacitor uses a first liquid electrolyte and the lithium ion battery uses the first liquid electrolyte. 
     In other features, the bipolar capacitor uses a first liquid electrolyte and the lithium ion battery uses a second liquid electrolyte that is different than the first liquid electrolyte. The bipolar capacitor uses a liquid electrolyte and the lithium ion battery uses a solid electrolyte. The bipolar capacitor uses a solid electrolyte and the lithium ion battery uses a liquid electrolyte. The bipolar capacitor uses a solid electrolyte and the lithium ion battery uses a solid electrolyte. 
     In other features, the lithium ion battery is bipolar and includes M lithium ion batteries connected in series, where M is an integer greater than one. The lithium ion battery comprises a third anode connected to the first negative terminal. A third separator is connected to the third anode. A first cathode is connected to the third separator. A first current collector is connected to the first cathode. A fourth anode is connected to the first current collector. A fourth separator is connected to the fourth anode. A second cathode is connected to the fourth separator. A second current collector connected to the second cathode. A fifth anode is connected to the second current collector. A fifth separator is connected to the fifth anode. A third cathode is connected to the fifth separator. A second positive terminal is connected to the third cathode. 
     In other features, a blocking material is arranged on at least the first separator, the second separator and the third separator of the lithium ion battery. The bipolar capacitor uses a first liquid electrolyte and the lithium ion battery uses the first liquid electrolyte. 
     In other features, the bipolar capacitor uses a first electrolyte and the lithium ion battery uses a second electrolyte that is different than the first electrolyte. The bipolar capacitor uses a first liquid electrolyte and the lithium ion battery uses a second liquid electrolyte that is different than the first liquid electrolyte. The bipolar capacitor uses a solid electrolyte and the lithium ion battery uses a liquid electrolyte. The bipolar capacitor uses a liquid electrolyte and the lithium ion battery uses a solid electrolyte. The bipolar capacitor uses a solid electrolyte and the lithium ion battery uses a solid electrolyte. 
     In other features, the bipolar capacitor comprises a lithium ion capacitor (LIC). 
     In other features, the bipolar capacitor comprises an electric double layer capacitor (EDLC). 
     Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present disclosure will become more fully understood from the detailed description and the accompanying drawings, wherein: 
         FIG.  1    illustrates an example of a bipolar capacitor assisted battery (BCAB) including a bipolar capacitor and a Li-Ion battery (LIB) according to the present disclosure; 
         FIG.  2    is an electrical schematic of the BCAB of  FIG.  1   ; 
         FIG.  3    illustrates an example of a bipolar capacitor assisted battery (BCAB) including a bipolar capacitor and a bipolar Li-Ion battery (LIB) according to the present disclosure; 
         FIG.  4    is an electrical schematic of the BCAB of  FIG.  3   ; 
         FIGS.  5 - 12    illustrate additional examples of BCABs according to the present disclosure; and 
         FIGS.  13 - 15    illustrate additional examples of bipolar capacitors according to the present disclosure. 
       In the drawings, reference numbers may be reused to identify similar and/or identical elements. 
     
    
    
     DETAILED DESCRIPTION 
     While a bipolar capacitor assisted battery (BCAB) is described below for a battery system of a battery electric vehicle, the bipolar capacitor assisted battery can be used in hybrid or other vehicles and/or in non-vehicle applications. 
     A capacitor assisted battery (CAB) includes a capacitor connected in parallel to a battery such as a lithium-ion battery (LIB). CABs can be used in high power output applications up to about 4 V. Currently the CABs use relatively low-voltage chemistry, such as lithium ion phosphate (LFP)/ graphite (Gr) and active carbon (AC). Use of CABs in higher voltage designs greater than about 4.25 V is limited by the capacitor in the CAB, which has low stability at high voltage and generates gas (especially when subjected to both elevated temperatures and high voltages). 
     A bipolar capacitor assisted battery (BCAB) according to the present disclosure improves the stability of CABs and extends the usage of CABs to high-voltage chemical system with longer cycle life and enhanced power output as compared to LIBs without changing cell chemistry. 
     The BCAB according to the present disclosure combines a bipolar-type capacitor and a Li-ion battery. Two or more capacitors are connected in series and then connected in parallel to a lithium-ion battery. The BCABs according to the present disclosure improve the electrochemical stability of CABs and extend the usage of CABs at higher voltage. 
     In a CAB, the capacitor and the LIB are connected in parallel in a battery cell such as a pouch-type battery cell. In this configuration, V cell  = V C  = V LIB . The stable window of the capacitor is narrower than the LIB. For example, if Vc &lt; 4.0 V, the LIB cannot adopt a high-voltage system that is greater than or equal to 4 V, such as NCM811/Gr or LiNi 0.5 Mn 1.5 O 4 /Gr. 
     To address this situation, the voltage of LIB can be limited (which reduces energy density), LIB chemistry can be limited (which reduces energy density), and/or complex control systems with switches can be used to control voltage across the capacitor (which increases cost and complexity). 
     In the BCAB, N capacitors are connected in series and then connected in parallel to the LIB. When N=2 capacitors are used, V cell  = 2 × V C  = V LIB . The sum of the voltage of the two or more capacitors equals to the voltage of the LIB. For example only, the LIB with lithium nickel cobalt manganese oxides (NCM)/Gr has voltage of about 4.4 V. When 2 capacitors are connected in series to the LIB, each capacitor works below about 2.2 V, which is a safe voltage. For a LIB with lithium nickel manganese oxide (LNMO)/Gr, the voltage is ~5 V and the voltage of each capacitor is 2.5 V, which is still a safe voltage. As can be appreciated, the BCAB according to the present disclosure enables high voltage use of CABs, enables high voltage LIB chemistry, enhances energy density, and avoids the use of switches. 
     Referring now to  FIGS.  1  and  2   , a bipolar capacitor assisted battery (BCAB)  10  and an equivalent circuit are shown, respectively. In  FIG.  1   , the BCAB  10  includes a bipolar capacitor  12  and a lithium ion battery (LIB)  14 . In this example, the bipolar capacitor  12  comprises N capacitors connected in series (N is an integer greater than one). In order of adjacent layers from left to right, the bipolar capacitor  12  includes a positive terminal  38 , a first capacitor  16  including a capacitor electrode (CE), a separator (S), and an anode (A), a current collector  24 , a second capacitor  18  including a capacitor electrode (CE), a separator (S), and an anode (A), and a negative terminal  40 . In some examples, a blocking material  20  may be used to prevent exposure and/or mixing of electrolyte. The blocking material  20  may extend over an exposed outer surface of the bipolar capacitor  12  or limited to exposed edges of the separators S of the bipolar capacitor  12 , 
     The LIB  14  abuts the negative terminal  40  and includes (in order of adjacent layers from left to right) an anode (A), a separator (S), a collector (C), positive terminal  42 , a collector (C), a separator (S), an anode (A), a negative terminal  44 , an anode (A), a separator (S), a collector (C), a positive terminal  46 , a collector (C), a separator (S), an anode (A), and a negative terminal  48 . 
     In  FIG.  2   , the BCAB  10  includes N series connected capacitors providing V C1 , V C2 , ..., and V CN  (where N is an integer greater than one). The series connected capacitors are connected in parallel to the LIB (providing V LIB ). Since the N capacitors are connected in parallel, each of the capacitors only needs to withstand 1/N of the voltage of the LIB. 
     Referring now to  FIGS.  3  and  4   , a bipolar capacitor assisted battery (BCAB)  100  and an equivalent circuit are shown, respectively. In  FIG.  1   , the BCAB  100   includes the bipolar capacitor  12  described in  FIG.  1    and a bipolar Li-Ion battery (LIB)  114 . 
     The LIB  114  abuts the negative terminal  40  of the bipolar capacitor  12  and includes (in order of adjacent layers from left to right) an anode (A), a separator (S), a collector (C), a current collector  132 , an anode (A), a separator (S), a collector (C), a current collector  134 , an anode (A), a separator (S), a collector (C), and a negative terminal  136 . In some examples, a blocker  140  may be used to prevent mixing and/or exposure of the electrolyte and/or exposure to the higher potential of the bipolar LIB. 
     In  FIG.  4   , the BCAB  100  includes N series connected capacitors providing V C1 , V C2 , ..., and V CN . The series connected capacitors are connected in parallel to M series-connected LIBs providing V LIB1 , V LIB2 , ..., and V LIBM . N and M are integers greater than one. In various examples, N &lt; M, N &gt; M or N=M. 
     Referring now to  FIGS.  5  and  6   , the bipolar capacitor and the LIB (or bipolar LIB) can use different liquid electrolyte. In  FIG.  5   , a BCAB  210  includes a bipolar capacitor  212  and a LIB  214 . The bipolar capacitor  212  comprises (in order of adjacent layers from left to right) a positive terminal  38 , a first capacitor  216  including a capacitor electrode (CE), a first liquid electrolyte (E 1 ), and an anode (A), the current collector  24 , a second capacitor  218  including a capacitor electrode (CE), the first liquid electrolyte (E 1 ), and an anode (A), and the negative terminal  40 . 
     The LIB  214  abuts the negative terminal  40  and includes (in order of adjacent layers from left to right) an anode (A), a second liquid electrolyte (E 2 ), a collector (C), the positive terminal  42 , a collector (C), the second liquid electrolyte (E 2 ), an anode (A), the negative terminal  44 , an anode (A), the second liquid electrolyte (E 2 ), a collector (C), the positive terminal  46 , a collector (C), the second liquid electrolyte (E 2 ), an anode (A), and the negative terminal  48 . The first and second liquid electrolytes are different. 
     In  FIG.  6   , the BCAB  310  includes a bipolar capacitor  312  and a bipolar Li-Ion battery (LIB)  314 . The bipolar capacitor  312  comprises (in order of adjacent layers from left to right) the positive terminal  38 , a first capacitor  316  including a capacitor electrode (CE), a first liquid electrolyte (E 1 ), and an anode (A), the current collector  24 , a second capacitor  318  including a capacitor electrode (CE), the first liquid electrolyte (E 1 ), and an anode (A), and the negative terminal  40 . 
     The LIB  314  abuts the negative terminal  40  of the bipolar capacitor  312  and includes (in order of adjacent layers from left to right) an anode (A), a second liquid electrolyte (E 2 ), a collector (C), the current collector  132 , an anode (A), the second liquid electrolyte (E 2 ), a collector (C), the current collector  134 , an anode (A), the second liquid electrolyte (E 2 ), a collector (C), and the negative terminal  136 . 
     Referring now to  FIGS.  7  and  8   , the bipolar capacitor and the LIB (or bipolar LIB) can use liquid and solid electrolyte, respectively. In  FIG.  7   , a BCAB  410  includes a bipolar capacitor  412  and a LIB  414 . The bipolar capacitor  412  comprises (in order of adjacent layers from left to right) the positive terminal  38 , a first capacitor  416  including a capacitor electrode (CE), a liquid electrolyte (LE), and an anode (A), the current collector  24 , a second capacitor  418  including a capacitor electrode (CE), the liquid electrolyte (LE), and an anode (A), and the negative terminal  40 . 
     The LIB  414  abuts the negative terminal  40  of the bipolar capacitor  412  and includes (in order of adjacent layers from left to right) an anode (A), a solid electrolyte (SE), a collector (C), the positive terminal  42 , a collector (C), the solid electrolyte (SE), an anode (A), the negative terminal  44 , an anode (A), the solid electrolyte (SE), a collector (C), the positive terminal  46 , a collector (C), the solid electrolyte (SE), an anode (A), and the negative terminal  48 . 
     In  FIG.  8   , the BCAB  510  includes a bipolar capacitor  512  and a bipolar Li-Ion battery (LIB)  514 . The bipolar capacitor  512  comprises (in order of adjacent layers from left to right) the positive terminal  38 , a first capacitor  516  including a capacitor electrode (CE), a liquid electrolyte (LE), and an anode (A), the current collector  24 , a second capacitor  518  including a capacitor electrode (CE), the liquid electrolyte (LE), and an anode (A), and the negative terminal  40 . 
     The LIB  514  abuts the negative terminal  40  of the bipolar capacitor  512  and includes (in order of adjacent layers from left to right) an anode (A), a solid electrolyte (SE), a collector (C), the current collector  132 , an anode (A), the solid electrolyte (SE), a collector (C), the current collector  134 , an anode (A), the solid electrolyte (SE), a collector (C), the current collector  137 , an anode (A), the solid electrolyte (SE), a collector (C), and the negative terminal  139 . 
     Referring now to  FIGS.  9  and  10   , the bipolar capacitor and the LIB or bipolar LIB can used solid and liquid electrolyte, respectively. In  FIG.  9   , a BCAB  610  includes a bipolar capacitor  612  and a LIB  614 . The bipolar capacitor  612  comprises (in order of adjacent layers from left to right) the positive terminal  38 , a first capacitor  616  including a capacitor electrode (CE), a solid electrolyte (SE), and an anode (A), the current collector  24 , a second capacitor  618  including a capacitor electrode (CE), the solid electrolyte (SE), and an anode (A), and the negative terminal  40 . 
     The LIB  614  abuts the negative terminal  40  of the bipolar capacitor  612  and includes (in order of adjacent layers from left to right) an anode (A), a liquid electrolyte (LE), a collector (C), the positive terminal  42 , a collector (C), the liquid electrolyte (LE), an anode (A), the negative terminal  44 , an anode (A), the liquid electrolyte (LE), a collector (C), the positive terminal  46 , a collector (C), the liquid electrolyte (LE), an anode (A), and the negative terminal  48 . 
     In  FIG.  10   , a BCAB  710  includes a bipolar capacitor  712  and a bipolar Li-Ion battery (LIB)  714 . The bipolar capacitor  712  comprises (in order of adjacent layers from left to right) the positive terminal  38 , a first capacitor  716  including a capacitor electrode (CE), a solid electrolyte (SE), and an anode (A), the current collector  24 , a second capacitor  718  including a capacitor electrode (CE), the solid electrolyte (SE), and an anode (A), and the negative terminal  40 . 
     The LIB  714  abuts the negative terminal  40  of the bipolar capacitor  712  and includes (in order of adjacent layers from left to right) an anode (A), a liquid electrolyte (LE), a collector (C), the current collector  132 , an anode (A), the liquid electrolyte (LE), a collector (C), the current collector  134 , an anode (A), the liquid electrolyte (LE), a collector (C), the current collector  137 , an anode (A), the liquid electrolyte (LE), a collector (C), and the negative terminal  139 . 
     Referring now to  FIGS.  11  and  12   , the bipolar capacitor and the LIB or bipolar LIB use solid electrolyte. In  FIG.  11   , a BCAB  750  includes a bipolar capacitor  752  and a LIB  754 . The bipolar capacitor  752  comprises (in order of adjacent layers from left to right) the positive terminal  38 , a first capacitor  756  including a capacitor electrode (CE), a solid electrolyte (SE), and an anode (A), the current collector  24 , a second capacitor  758  including a capacitor electrode (CE), the solid electrolyte (SE), and an anode (A), and the negative terminal  40 . 
     The LIB  754  abuts the negative terminal  40  of the bipolar capacitor  752  and includes (in order of adjacent layers from left to right) an anode (A), a solid electrolyte (SE), a collector (C), the positive terminal  42 , a collector (C), the solid electrolyte (SE), an anode (A), the negative terminal  44 , an anode (A), the solid electrolyte (SE), a collector (C), the positive terminal  46 , a collector (C), the solid electrolyte (SE), an anode (A), and the negative terminal  48 . 
     In  FIG.  12   , a BCAB  760  includes a bipolar capacitor  762  and a bipolar Li-Ion battery (LIB)  764 . The bipolar capacitor  762  comprises (in order of adjacent layers from left to right) the positive terminal  38 , a first capacitor  766  including a capacitor electrode (CE), a solid electrolyte (SE), and an anode (A), the current collector  24 , a second capacitor  768  including a capacitor electrode (CE), the solid electrolyte (SE), and an anode (A), and the negative terminal  40 . 
     The LIB  764  abuts the negative terminal  40  of the bipolar capacitor  762  and includes (in order of adjacent layers from left to right) an anode (A), a solid electrolyte (SE), a collector (C), the current collector  132 , an anode (A), the solid electrolyte (SE), a collector (C), the current collector  134 , an anode (A), the solid electrolyte (SE), a collector (C), the current collector  137 , an anode (A), the solid electrolyte (SE), a collector (C), and the negative terminal  139 . 
     Referring now to  FIGS.  13  to  15   , the bipolar capacitor can have various different configurations. In  FIGS.  13  and  14   , the bipolar capacitor is a lithium ion capacitor (LIC). In  FIG.  15   , the bipolar capacitor is an electric double layer capacitor (EDLC). 
     In  FIG.  13   , a bipolar capacitor  810  includes a positive terminal  812 , a capacitor electrode (CE), a separator (S), a Li-Ion insertion electrode (LiIE), a current collector  814 , a capacitor electrode (CE), a separator (S) and a Li-Ion insertion electrode (LiIE), and a negative terminal  816 . 
     In  FIG.  14   , a bipolar capacitor  830  includes the positive terminal  812 , a Li-Ion insertion electrode (LiIE), a separator (S), a capacitor electrode (CE), a current collector  814 , a Li-Ion insertion electrode (LiIE), a separator (S), a capacitor electrode (CE), and the negative terminal  816 . 
     In some examples, the positive electrode/negative electrode of LIC bipolar capacitor include faradic active carbon (AC) and lithium titanium oxide (LTO), lithium manganese oxide (LMO) and AC, AC and graphite (Gr), and/or other suitable material combinations. 
     In  FIG.  15   , a bipolar capacitor  840  includes the positive terminal  812 , a a capacitor electrode (CE), a separator (S), a capacitor electrode (CE), a current collector  814 , a capacitor electrode (CE), a separator (S), a capacitor electrode (CE), and the negative terminal  816 . In some examples, the positive electrode/negative electrode couple include non-faradic AC and AC and/or other suitable material combinations. 
     In other examples, a bipolar capacitor can include EDLC/LIC pseudo-capacitance such as AC and manganese oxide (MnO 2 ), MnO 2  and AC, AC and nickel oxide (NiO), NiO and AC, and/or other suitable material combinations. 
     The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure. 
     Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.” 
     In the figures, the direction of an arrow, as indicated by the arrowhead, generally demonstrates the flow of information (such as data or instructions) that is of interest to the illustration. For example, when element A and element B exchange a variety of information but information transmitted from element A to element B is relevant to the illustration, the arrow may point from element A to element B. This unidirectional arrow does not imply that no other information is transmitted from element B to element A. Further, for information sent from element A to element B, element B may send requests for, or receipt acknowledgements of, the information to element A.