BIOMATERIAL ELECTROLYTE FOR AN EVERLASTING BATTERY

Abstract

A battery and battery electrolyte components are provided including pyocyanin. Methods for making a biomaterial battery include: providing an oxygen permeable anode layer; depositing an oxygenated purified metabolite comprising pyocyanin on the oxygen permeable anode membrane; covering the oxygenated purified metabolite with a bacterial cellulose ion-exchange membrane; depositing a non-oxygenated purified metabolite on the bacterial cellulose ion-exchange membrane; and covering the oxygenated purified metabolite with a cathode layer. The battery is configured to produce a current density of about 3.2 A/m.sup.2 at constant voltage of about 2.2 V.

Claims

1. A battery comprising: a cathode comprising carbon; a first electrolyte layer; a separator membrane comprising bacterial cellulose; a second electrolyte layer; and an anode comprising copper, wherein at least one of the first electrolyte layer and the second electrolyte layer comprises pyocyanin.

2. The battery according to claim 1, wherein the pyocyanin is harvested from Pseudomonas Aeruginosa.

3. The battery according to claim 1, wherein the first electrolyte layer comprises an oxygenized electrolyte, and the second electrolyte layer comprises a deoxygenized electrolyte.

4. The battery according to claim 1, integrated into a thin sheet of paper configured for use with paper electronics.

5. The battery according to claim 1, comprising an area (length and width) dimension of about 25 cm.sup.2, wherein the battery is provided with a total thickness of about 300 m.

6. The battery according to claim 1, configured to produce a current density of about 3.2 A/m.sup.2 at constant voltage of about 2.2 V.

7. The battery according to claim 1, wherein oxygen is added to create electricity, and oxygen is released when the electricity is consumed.

8. The battery according to claim 1, wherein the first electrolyte and second electrolyte are free from Pseudomonas Aeruginosa.

9. A method of making a biomaterial battery, the method comprising: providing an oxygen permeable anode layer; depositing an oxygenated purified metabolite comprising pyocyanin on the oxygen permeable anode membrane; covering the oxygenated purified metabolite with a bacterial cellulose ion-exchange membrane; depositing a non-oxygenated purified metabolite on the bacterial cellulose ion-exchange membrane; and covering the oxygenated purified metabolite with a cathode layer.

10. The method according to claim 9, wherein the anode comprises copper, and the cathode comprises carbon.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present teachings will become more fully understood from the detailed description and the accompanying drawings, wherein:

[0022] FIG. 1 illustrates the green medium before and after centrifugation according to various aspects of the present technology;

[0023] FIG. 2 is an exemplary centrifuge useful with the present technology;

[0024] FIG. 3 illustrates (to the left) the yellow solution prepared by air extracting, and (to the right) the green electrolyte prepared by air pumping;

[0025] FIG. 4 illustrates the three electrode cell used for the voltammetry study;

[0026] FIG. 5 is an exemplary battery design showing five layers;

[0027] FIG. 6 is a voltammogram of the green electrolyte; and

[0028] FIGS. 7 and 8 are plots showing voltage vs. capacity as discharging characterization and charging characterization graphs.

[0029] It should be noted that the figures set forth herein are intended to exemplify the general characteristics of the methods, algorithms, and devices among those of the present technology, for the purpose of the description of certain aspects. These figures may not precisely reflect the characteristics of any given aspect, and are not necessarily intended to define or limit specific embodiments within the scope of this technology. Further, certain aspects may incorporate features from a combination of figures.

DETAILED DESCRIPTION

[0030] Nowadays, daily life is highly dependent on mobile electronic devices and the need of everlasting mobile power sources is increasing. The most common batteries used in modern electronics are lithium ions batteries (LIB) known for their light weight, high energy density and long life cycle. However among the disadvantages of LIB are their relatively high cost and safety hazards. By looking for a greener and safer energy source, electrical power was harvested from microorganism in a microbial fuel cell (MFC). In fact, bacteria can generate electric power by transforming the chemical energy of the biomass to electricity. An important advantage of MFC is that it can be miniaturized and integrated into a thin sheet of paper fulfilling the needs of modern paper electronics. The current density and voltage of such cells ranges from 0.08 to 0.98 A/cm.sup.2.

[0031] The thin battery of the present technology, that uses this MFC, combines LIB high energy density and long life cycle to the eco-friendly trend. The battery of the present technology makes use of a bacterial metabolite that undergoes redox reactions. In various aspects, the approximately 25 cm.sup.2 dimensioned thin battery is composed of 5 layers having a total thickness of about 300 m. In one exemplary method of making the battery, about 250 l of an oxygenated purified metabolite (second layer) is deposited on an oxygen permeable anode membrane (first layer) and is covered by a bacterial cellulose ion-exchange membrane (third layer). Another 250 l of non-oxygenated purified metabolite (fourth layer) is deposited on the bacterial cellulose membrane and covered by the cathode (fifth layer). This structure produced a battery with a current density of about 3.2 A/m.sup.2 at constant voltage of about 2.2V. The power density does not show any decrease with load and is stable over a 7 days observation period. A voltammogram indicates that the process is reversible and fast. Such values are much higher than those obtained by any bacterial fuel cell. It is important to note that this new battery uses oxygen to create electricity, and releases it back when the electricity is consumed. The battery can be integrated into a thin sheet of paper configured for use with paper electronics. The future development of this green, always-fully-charged battery can lead to their use for mobile devices and electric vehicles.

[0032] The present technology generally provides new bacterial fuel cells that can produce a continuous current of 3.2 Am.sup.2 at a voltage of 2.2 V. The main principle is based on a redox reaction of pyocyanin, produced by Pseudomonas aeruginosa. At the anode, the O.sub.2 oxidizes the pyocyanin, which generates free electrons that are captured by the anode and transferred to the cathode where a reduction reaction takes place.

Materials and Methods

Bacteria Growth and Identification

[0033] The Pseudomonas aeruginosa can be originated from agriculture waste and isolated on HS agar medium. The yellow agar turns to green after 24 hours of incubation at a temperature of about 28 Celsius. After the HS agar medium turns into green color the bacterium is inoculated in HS liquid medium. After about 48 hours, the medium starts turning green when the flask is agitated.

Electrolyte Preparation

Pyocyanin Extraction

[0034] Pyocyanin is extracted from the liquid growth medium using bench top centrifuge. FIG. 1 shows the solution before and after centrifugation.

Protein Precipitation

[0035] The protein precipitation is done using ethanol. After centrifugation, 5% (volume) of ethanol is added to the solution and centrifugation for 5 minutes is applied again. After centrifugation, the solution is heated at 70 C. until 50% of the solution is evaporated.

Oxygenized/Deoxygenized Electrolyte

[0036] Two different electrolytes are prepared: Oxygenized (green electrolyte) and deoxygenized (yellow electrolyte). The green electrolyte is prepared by bubbling air in the solution, while the yellow electrolyte is prepared by extracting the oxygen from the solution using a vacuum pump. FIG. 3 shows the 2 different electrolytes prepared.

Electrochemical Study

[0037] A voltammetry study is done on the green electrolyte using a 3 electrode cell. Electrodes used and the voltammetry properties are shown in FIG. 4 and provided below. The working electrodes are carbon and copper. The reference electrode is AgCl. Voltammetry properties are as follows:

[0038] Potential sweep: v=90 mV/s

[0039] Potential range: [5V; +5V]

[0040] Number of cycles: 3

[0041] Thin Battery Design

[0042] The thin battery is composed of 5 layers as illustrated in FIG. 5. Layer 1: carbon layer that serve as a cathode (bottom layer); Layer 2: 0.25 ml of green electrolyte, also referred to as the oxygenized electrolyte layer; Layer 3: separator membrane from bacterial cellulose (middle layer); Layer 4: 0.25 ml of yellow electrolyte, also referred to as the deoxygenized electrolyte layer; and Layer 5: copper layer as anode (top layer). The battery dimensions are 250.03 cm.sup.3.

Charging and Discharging Characterization

[0043] In order to evaluate the charging and discharging capacity of the battery, a cell is cyclically charged and discharged at a constant low current and between upper and lower voltage limit. The cell is first charged at a constant current rate to the upper voltage limit. After charging, the input current is set to zero for 10 minutes. Then, the cell is discharged to the lower voltage limit.

Results and Discussions

Voltammetry Study

[0044] The voltammogram in FIG. 6 shows 2 peaks: an anodic peak E.sub.pa at 3.83V and a cathodic peak E.sub.pa at 3.8V. The intensities of the peaks are: Ipa=4.62 mA for E.sub.pa and Ipc=4.61 mA for E.sub.pc.

TABLE-US-00001 TABLE 1 Potential and Current Values at the Peaks. E.sub.pa (V) 3.83 E.sub.pc (V) 3.80 Ipa (mA) 4.62 Ipc (mA) 4.61

[0045] Regarding Nernst equation, to have a reversible reaction, the values of the potentials and the currents should respect the below equations:

[00001]$.Math..Math.E_p=.Math.E_{\mathrm{pa}}-E_{\mathrm{pc}}.Math.=\frac{0.059}{n};$

n: nb. of electrons gained by reduction

[00002]$\frac{I_{\mathrm{pc}}}{I_{\mathrm{pa}}}=1$

[0046] Applying our values in those 2 equations we find that E.sub.p=|E.sub.paE.sub.pc|=0.03 and

[00003]$\frac{I_{\mathrm{pc}}}{I_{\mathrm{pa}}}=1$

[0047] Regarding those results, the reaction that take place is a reversible reaction with 2 electrons transfer during the reduction.

Thin Battery Characteristics

[0048] Table 2, provided below, lists various characteristics of the thin battery of the present technology. In particular, the battery characteristics show that the battery according to the present technology has a high energy density and small dimensions, and it respects the ecofriendly trend. Regarding those values, this biomaterial battery can be the future technology for battery industry that generates electrical energy better than any other renewable source of energy and can be adopted and personalized to be used for all electronics devices and vehicles.

TABLE-US-00002 TABLE 2 Battery Characteristics Current (A/m.sup.2) 3.2 Voltage (V) 2.2 Toxicity Non toxic Dimensions (cm.sup.3) 2 5 0.03 Operating temperature (C.) [20; 120] Heat emission no

Charging and Discharging Characteristics

[0049] FIGS. 7 and 8 illustrate the charging and discharging characterizations of the biomaterial cell. The discharging characterization is identical for a Lithium ion battery; approximately they both have the same time of discharging and internal resistance. Concerning the charging characterization, the biomaterial battery charges faster than an ordinary Li ion battery.

[0050] The foregoing description is provided for purposes of illustration and description and is in no way intended to limit the disclosure, its application, or uses. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations should not be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.

[0051] 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. It should be understood that the various steps within a method may be executed in different order without altering the principles of the present disclosure. Disclosure of ranges includes disclosure of all ranges and subdivided ranges within the entire range, including the endpoints.

[0052] The headings (such as Background and Summary) and sub-headings used herein are intended only for general organization of topics within the present disclosure, and are not intended to limit the disclosure of the technology or any aspect thereof. The recitation of multiple embodiments having stated features is not intended to exclude other embodiments having additional features, or other embodiments incorporating different combinations of the stated features.

[0053] As used herein, the terms comprise and include and their variants are intended to be non-limiting, such that recitation of items in succession or a list is not to the exclusion of other like items that may also be useful in the devices and methods of this technology. Similarly, the terms can and may and their variants are intended to be non-limiting, such that recitation that an embodiment can or may comprise certain elements or features does not exclude other embodiments of the present technology that do not contain those elements or features.

[0054] The broad teachings of the present 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 to the skilled practitioner upon a study of the specification and the following claims. Reference herein to one aspect, or various aspects means that a particular feature, structure, or characteristic described in connection with an embodiment or particular system is included in at least one embodiment or aspect. The appearances of the phrase in one aspect (or variations thereof) are not necessarily referring to the same aspect or embodiment. It should be also understood that the various method steps discussed herein do not have to be carried out in the same order as depicted, and not each method step is required in each aspect or embodiment.