WO2022058099A2

WO2022058099A2 - Battery supercapacitors hybrid systems

Info

Publication number: WO2022058099A2
Application number: PCT/EP2021/072610
Authority: WO
Inventors: Mohamad KABBANI
Original assignee: Shell Oil Company; Shell Internationale Research Maatschappij B.V.
Priority date: 2020-09-18
Filing date: 2021-08-13
Publication date: 2022-03-24
Also published as: WO2022058099A3

Abstract

A battery supercapacitor hybrid system using a double hybridization electrodes configuration via the chemical integration of different carbon and LTO -based nanomaterials components, including hybrids of lithium carboxylated CNTs and graphene, different types of functionalized carbon-based nanomaterials, crystalline nano-sized/nanostructured LTO embedded in carbon and LIB components.

Description

BATTERY SUPERCAPACITORS HYBRID SYSTEMS

Field of the Invention

Batteries and supercapacitors (SCs) are complementary as energy storage systems. Typically, batteries have a longer capability for storing energy while SCs can permit the rapid release of the stored energy. As a result, SCs are highly attractive for military applications, emerging mobile devices, and for the automotive industry (which includes electric vehicles), due to their very long service life, fast charging abilities, and are considered by many to be safer than most batteries.

Recent years has seen a growth among large vehicle manufacturers who are gradually electrifying their fleets either with full battery electric vehicles (BEV) or hybrid electric vehicles (HEV). This shift has resulted in new requirements for batteries and vehicle concepts ranging from large batteries, designed for a full day of operation without charging, to fastcharging systems with charging power up to a few hundred kilowatts. These increased requirements have caused the identification of many different issues in the whole design and production process regarding high-voltage (HV) batteries for transportation. The U.S. Department of Energy has the following targets for BEVs:

• Reducing of the production cost of a BEV battery to 80 dollars /kWh

• Increasing the range of EVs to 300 miles

• Decreasing charge time to 15 minutes

See U.S. Department of Energy report on: Enabling Fast Charging, a technology gap assessment, October 2017.

The rapid increase in deployment of battery technology has been due to progress in lithium -ion batteries (LIBs). Since their introduction to the market in 1991, LIBs have transformed portable electronics from powering laptops and cell phones, to serving a backup energy supply in numerous electronic applications. New generations of such batteries are expected to electrify transport and find use in stationary electricity storage. However, even when fully developed, the highest performance that LIBs can deliver is still not optimal to meet the demands of key markets, such as transport in the long term. However, other example of alternative solutions is the recent development in the world of SCs that have the potential especially with their battery hybrids (BSH) to compete with petroleum -based energy sources, both in terms of cost and performance, with very fast recharging and long-life cycling capabilities.

The hybridization of SCs and batteries enables the direct integration of high energy from batteries and high power and long lifetime from SCs. The energy storage mechanism of BSHs is as follows: during charging or discharging, anions and cations move to (or separate from) the two electrodes, respectively, and bulk redox reactions occur at the battery-type electrode while ion accumulation/separation or rapid charge transfer happen at the capacitive electrode; at the meantime, the electrons flow across the external circuit. As Li-ion type of electrodes have high specific capacity, LIB-BSH can bridge the gap between LIBs and SCs and have attracted worldwide attention since the first Li-ion based BSH was developed in the early 2000s. See U.S. Pat. No. 6,252,762.

Early BSHs were assembled using a nanostructured spinel Li^isOn (LTO) anode (battery-type electrode) and an activated carbon (AC) cathode (capacitor-type electrode). These devices utilized Li⁺ intercalation (i.e., Faradaic process) and electric double-layer capacitance (i.e., non-Faradaic process) to store energy. Upon charging, Li⁺ ions from the organic liquid electrolyte LiPF6 diffuse towards and intercalate into the negative electrode, electrons from the positive electrode, passed through the external circuit, reduce Ti⁴⁺ to Ti³⁺, and spinel LiNi CU changes phase to rock-salt LiyTisOn where three Ti ⁺⁴ are reduced to Ti⁺³ during the phase transition as described by the half-reaction:

[Spinel -LTO ] Li₄Ti₅ (IV)Oi₂ +3 Li+1 +3e -^Li₇Ti2(IV)Ti₃(in)Oi2 [rock-salt LTO]

Charge separation (polarization) at the positive electrode leaves positively-charged AC surface, onto which the electrolyte anions PF6- adsorb, and electric double-layer is formed.

The electrochemical processes taking place within these early systems are shown in the simplified schematic of Figure 1. Hybridization done by combining a battery electrode with a capacitor electrode is called single hybridization. An example of an early BSH represented by figure 1 was based on a single hybridization configuration , which is a common type for current BSH devices .

Maximal energy stored by a capacitor is given by E_c ⁼¹/2CV². Accordingly, the higher the possible potential in which the device can be operated, without redox interference by solution redox reactions, the higher the energy density can be reached. Nonaqueous electrolytes have electrochemical potential windows as wide as 4-5 volts as compared to 1.2 volts for aqueous solutions. Therefore, nonaqueous electrolytes show promise as possible candidates as electrolyte solutions for supercapacitors for higher energy density. Accordingly, the energy density electrochemical capacitors are mainly controlled by the capacitance of the electrode material.

Prior art activated carbon SCs have a high surface area — typically ranging from 1000- 2000 m² — but very low mesoporosity resulting in poor accessibility of ions. The low accessibility together with its relatively poor electrical conductivity produce a high internal resistance and hence a low power density, Accordingly, limited energy density (e.g., 4-5 Wh kg'¹) and power density (e.g., 1-2 Kw kg'¹) have been observed for activated carbon-based SCs. Therefore, new materials are needed to improve the performance of SCs. Due to their large surface area, high mesoporosity, improved electrical properties as well as improved mechanical properties carbon nanomaterials, especially carbon nanotubes (CNTs) and graphene, have been considered as promising materials to replace activated carbon in the construction of SCs electrodes.

Up to now, various kinds of carbon-based nanomaterials electrodes such as CNTs and graphene have been used for the fabrication of supercapacitors, with graphene used more extensively than CNTs. One prior art strategy to materialize the potential of using such materials for SCs applications is to add some spacer to prevent restacking of graphene sheets or agglomeration of CNTs in such a way the spacer contributes to the active surface area and its conductivity. Recent techniques involve:

1. Vertically oriented graphene [VOG] sheets

2. In-plane all-solid graphene SCs

3. Curved graphene Nano sheets

4. CNTs Spaced graphene SCs

5. Chemically converted graphene (CCG) and self -stacked solvated graphene (SSSG) etc.

Li4TisOi2, as an engineering material for a hybrid capacitor system, inherently has several advantages, specifically in energy density and safety: (1) high columbic efficiency (>95% at 1 C) very close to the theoretical capacity of 175 mAh g^-1 (see T. Ohzuku, A. Yamamoto, J.Electrochem.Soc.142 (1995)1431; see a/ o M.M. Thackeray, J. Electrochem.Soc 142 (1995) 2558; see also A.N. Jansen et al. J. Power Sources 81-82 (1999) 902), (2) thermodynamically flat discharge profile at 1.55 V vs. Li/Li⁺ (see S. Schamer et al. J. Electrochem.Soc 146 (1999) 857), (3) zero-strain insertion that provides little volume change during charge-discharge (4) little electrolyte decomposition (little solid electrolyte interface and little gas evolution (see J. Shu, Electrochem. Solid-State Lett.11(2008) A238) and (5) inexpensive raw material. However, the greatest problem of Li^isOn is its low power characteristics that stem from inherent poor Li⁺ diffusion coefficient (<10^-6 cm² s^-1)¹⁵] and poor electronic conductivity (<10^-13 S cm^-1)¹⁶. Some prior art processes include grafted small nano-crystalline Li4Ti5O12 (5-20 nm) onto carbon nano-fibers [NC- Li4Ti5O12/CNF] to carbon nanotubes which show moderate energy densities and desirable power densities with less electrode stability and cyclic life for the BSHs. However, such prior art products are obtained under harsh conditions that endanger all the merits of the BSHs device resulting in poor conductivity, short range electrode stability, poor cycling and relatively low energy densities and low power densities.

Summary of the Invention

It has been found that limitations present in prior art systems may be overcome through the use of new techniques for the design of high performance BSH devices using a double hybridization electrodes configuration via the chemical integration of different carbon and LTO -based nanomaterials components. In some embodiments, these components involve hybrids of lithium carboxylated CNTs and graphene, different types of functionalized carbon-based nanomaterials, crystalline nano-sized/nanostructured LTO embedded in carbon and LIB components. Chemical integration of the functionalized CNTs and graphene may be enabled through multiple hydrogen bonding and pi-pi stabilization. Nano-LTO obtained via spray pyrolysis or wet chemical film deposition, results in a robust composite electrode through the control of the nucleation and growth and mixing state of the composite.

In some embodiments, a battery supercapacitor hybrid system comprises a lithium-ion battery type electrode, a non-aqueous electrolyte, and an electric double layer supercapacitor electrode (EDLC) wherein the EDLC further comprises carbon nanomaterials chemically decorated by lithium carboxylate groups. In some embodiments, the lithium carboxylate groups comprise MWCNT-(COO)xLix.

In some embodiments, a battery supercapacitor hybrid system comprises an anode material (A), a first supercapacitor electrode (S), and a second super capacitor electrode (S’), wherein the anode material comprises carbon nanotubes bonded with lithium carboxylate groups. In some embodiments, the first super capacitor electrode comprises a material selected from a group consisting of NH₂-MWCNT, OH-MWCNT, or H₂NCO-MWCNT. In some embodiments, the second supercapacitor electrode comprises F-MWCNT. In some embodiments, the first supercapacitor electrode comprises MWCNT-OH. In some embodiments, the second supercapacitor electrode comprises MWCNT-COGNQ.

In some embodiments, a battery supercapacitor hybrid system comprises an anode material (A), a first supercapacitor electrode (S), and a second super capacitor electrode (S’), wherein the anode material comprises graphene is bonded with lithium carboxylate groups. In some embodiments, the first supercapacitor electrode comprises G-OH. In some embodiments, the second supercapacitor electrode comprises G-COOH.

The features and advantages of the invention will be apparent to those skilled in the art. While numerous changes may be made by those skilled in the art, such changes are within the spirit of the invention.

Brief Description of the Drawings

A more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings and described herein. It is to be noted, however, that the appended drawings illustrate only some embodiments of the invention and therefore not to be considered limited of its scope for the invention may admit to other equally effective embodiments.

Fig. 1 is a schematic of a prior art single hybridization Li-ion BSH device with activated carbon cathode and LTO intercalation anode.

Fig. 2 is a schematic of double hybridization BSH architectures with LIB , LIB/C cathodes and anodes wiring possibilities.

Detailed Description of the Invention

According to some embodiments of the present invention the design of the battery supercapacitor hybrid systems depends mainly on the chemical integration of different components. The embodiments disclosed herein provides for an appreciable increase in both energy and power densities compared to current BSHs. Additionally, such embodiments ensure mechano-electrochemical compatibility and long lifetime of the BSHs. Furthermore, some embodiments minimize materials defects, folding and interfacial stress with the separator via chemical link. A wide spectrum of design alternatives confirm these appreciable benefits created by the present invention.

The overall energy can be further improved by using a double configuration as shown in Figure 2. In some embodiments, a hybrid electrode is fabricated and combined with a capacitive -type or battery-type electrode. Some embodiments of hybrid anodes wired to capacitive cathodes include LTO/C and LTO/Graphene, among others. Analogously, according to some embodiments, hybrid cathodes such as Lis V2(PO4)3/C may be fabricated and combined to a capacitive electrode. Furthermore, in some embodiments, hybrid anodes or cathodes may be wired to LIB electrodes, such as wiring LiM CU/AC to an LTO anode. A double hybridization electrode enhance both the kinetics and thermodynamics in a single energy storage device resulting in the increase of energy density power density and lifetime of the device.

According to some embodiments, a battery supercapacitor hybrid system comprises a lithium-ion battery type electrode and a supercapacitor electrode. The lithium-ion battery type electrode serves as a cathode for the BSH. In some embodiments the supercapacitor anode comprises an anode material (A), a first supercapacitor electrode (S), and a second super capacitor electrode (S’). In some embodiments, battery type electrode provides larger capacity than typical capacitive materials, resulting in higher energy density when compared to conventional lithium-ion batteries. In some embodiments, the supercapacitor anode functions via fast accumulation of charges, promotes power capability and cycling stability. Thus, the embodiments disclosure herein hav opened new horizons for emerging energy- storage vehicles that will bridge the gap between LIB and SC achieving energy comparable to LIB and power of SC.

In some embodiments, nano structuring reduces the ion diffusion pathway and hybridization at the nanoscale with target species such as CNTs or graphenes thereby increasing conductivity and stability, contrary to the sluggish redox processes that occur in prior art batterytype electrodes that hinder power performance.

In some embodiments, the anode of the battery supercapacitor hybrid system comprises carbon nanomaterials chemically decorated by lithium carboxylate groups. In some embodiments, the anode of the BSH comprises multi-walled carbon nano-tubes (MWCNT) or single walled carbon nano-tubes (SWCNT). In some embodiments, the carbon nanotubes are bonded with a lithium carboxylate groups such as, for example, MWCNT-(C00)x Lix. In some embodiments, the anode of the battery supercapacitor hybrid system may comprise different functionalized carbon combinations such as NH2-MWCNT/F-MWCNT, or MWCNT-OH /F- MWCNT and permuting these with different LIBs cathode combinations. A person of ordinary skill in the art would appreciate that functionalized carbon may refer to carbon having enhanced properties as a result of including functional groups with increase specific performance aspects of the carbon when used in specific implementations. In some embodiments, the anode of the BSH may comprise combinations of MWCNT-OH/MWCNT-COGNQ and permuting these with different LIB cathode combinations, where GNQ is quinolone.

In some embodiments, anode of the battery supercapacitor hybrid system comprises graphene (G) chemically decorated by lithium carboxylate groups. In some embodiments, the anode of the BSH comprises multi-layer graphene or single layer graphene. In some embodiments, the graphene is bonded with a lithium carboxylate groups such as, for example, G-(COO)x Lix. In some embodiments, the anode of the battery supercapacitor hybrid system may include different functionalized carbon combinations such as G-OH and G-COOH and permuting these with different LIB cathodes combinations.

TABLE 1 includes examples of the BSHs disclosed herein:

TABLE 1 : BSH Configurations

According to some embodiments, the hydrogen bonding between carboxylate Os, NH2 and between NH2/0H and F ensure a well-integrated and well-connected system. Additionally, in some embodiments lithium ions are free to move in at least two directions: i) through the interaction with the polar NH2, OH and amide group and, ii) via longitudinal propagation along the carbon nanotubes leading to high Coulombic efficiency. According to some embodiments, the hybrid systems disclosed herein promote the fast kinetics of the superconductor in addition to the high energy density of the lithium ion battery, combining to form a robust system. In some embodiments, graphene restacking is controlled and/or minimized via at least one of two mechanisms: (1) reactions between OH and COOH in functionalized graphene components; and (2) donor/acceptor interactions between the heterogenous graphene pi systems adding to the stability of the BSH system described herein. In some embodiments, the 3D nanostructured graphene systems reduce the diffusion of lithium ions resulting in high Coulombic efficiency.

Some embodiments of the disclosed BSH systems depend mainly on the chemical integration of different components. According to some embodiments, the BSHs provide considerable benefits over known alternatives, including: (1) an appreciable increase in both energy and power densities compared to current BSHs; (2) ensuring mechano-electrochemical compatibility and long lifetime of the BSHs; (3) minimizing materials defects, folding and interfacial stress with the separator via chemical links; (4) chemically integrated systems leave minimal surface defects where lithium plating can take place; and (5) wide spectrum of design alternatives.

The BSH systems disclosed herein provide considerable advantages over existing, prior art battery systems. For example, in some embodiments, the lithium ion is part of the conductive system (i.e., the electrodes) rather than being randomly disposed within the electrolyte eliminating any concern related to ion migration within the system. Additionally, the presence of multiple lithium ions on the surface of the nanocarbon electrode material may lead to an appreciable increase in energy density of the assembled cell while avoiding any instability due to insertion in intercalation type of electrodes. In some embodiments, the integral electrode system is well tuned and scaled according to simple chemical reaction and electrode preparation involves mild conditions that do not endanger electrical conductivity. Lithium diffusion is accelerated due to fast charge balance principles that are compatible with the supercapacitor fast kinetics. In some embodiments, lightweight carbon nanomaterials may appreciably enhance energy density relative to the relatively high weight of multiple titanium Ti=47.88 as compared to 12. The systems described herein are stable and safe of volume changes as lithium moves back and forth, and a wider range of material optimization is available using different types of carbon nanomaterial. Furthermore, a wide variety of different types of functionalized carbon nanomaterials may be used. In some embodiments, doped lithium functionalized carbon materials negative electrodes can be isolated from the positive electrodes using functionalized boron nitride nanotubes (BNNT) leading to better electrical transport in the disclosed BSH systems.

Claims

We claim:

1. A battery supercapacitor hybrid system comprising: a. A lithium-ion battery type electrode; b. A non-aqueous electrolyte; and c. An electric double layer supercapacitor electrode wherein the electric double layer supercapacitor electrode further comprises carbon nanomaterials chemically decorated by lithium carboxylate groups .

2. The system of claim 1 wherein the lithium carboxylate groups comprise MWCNT- (COO)xLix.

3. A battery supercapacitor hybrid system comprising: a. an anode material (A), a first supercapacitor electrode (S), and a second super capacitor electrode (S’); b. wherein the anode material comprises carbon nanotubes bonded with lithium carboxylate groups.

4. The system of claim 3 wherein the first supercapacitor electrode comprises a material selected from a group consisting of NH2-MWCNT, OH-MWCNT, or H2NCO- MWCNT.

5. The system of claim 3 wherein the second supercapacitor electrode comprises F- MWCNT.

6. The system of claim 3 wherein the first supercapacitor electrode comprises MWCNT- OH.

7. The system of claim 3 wherein the second supercapacitor electrode comprises MWCNT-COGNQ.

8. A battery supercapacitor hybrid system comprising: a. an anode material (A), a first supercapacitor electrode (S), and a second super capacitor electrode (S’); b. wherein the anode material comprises graphene bonded with lithium carboxylate groups. The system of claim 8 wherein the first supercapacitor electrode comprises G-OH. The system of claim 8 wherein the second supercapacitor electrode comprises G- COOH.