WO2016142927A1

WO2016142927A1 - An electrochemical solid carbon-sulfur li-ion based device and uses thereof

Info

Publication number: WO2016142927A1
Application number: PCT/IB2016/051451
Authority: WO
Inventors: Maria Helena SOUSA SOARES DE OLIVEIRA BRAGA; José Jorge DO AMARAL FERREIRA; Andrew Jackson MURCHISON JR
Original assignee: Sousa Soares De Oliveira Braga Maria Helena
Priority date: 2015-03-12
Filing date: 2016-03-14
Publication date: 2016-09-15

Abstract

The present disclosure relates to the development layered electrochemical solid devices, in particular to the development of a new device; a supercapacitor and or a battery solid carbon- sulfur Li-ion glassy electrolyte based device with autonomous dual functionality comprising a safe, environmentally friendly and inexpensive device. The present subject-matter relates to a layered electrochemical solid device comprising a positive electrode current collector, a positive electrode, a glass electrolyte, a negative electrode and a negative electrode current collector wherein the positive electrode current collector comprises aluminium; the positive electrode comprises sulfur, glass electrolyte and carbon; the electrolyte composition comprises a compound of formula Li3-2xMxHalO wherein: M is selected from the group consisting of boron, aluminium, magnesium, calcium, strontium, barium; Hal is selected from the group consisting of fluoride, chloride, bromide, iodide or mixtures thereof; X is the number of moles of M and 0 ˂ x ≤ 0.01; the negative electrode comprises a carbonaceous material; the negative electrode current collector comprises copper. The present subject-matter relates to a layered electrochemical solid device comprising the above described layers with inverted roles.

Description

D E S C R I P T I O N AN ELECTROCHEMICAL SOLID CARBON-SULFUR LI-ION BASED DEVICE AND USES THEREOF

Technical field

[0001] The present disclosure relates to the development and improvement of lithium-ion electrolyte composition, layered electrochemical solid devices, in pa rticular to the development of a new device; a supercapacitor and battery solid ca rbon-sulfur Li-ion based device with autonomous dual functiona lity which is charged from the Li-rich glassy electrolyte solid electrolyte glass comprising a safe, environmenta lly friendly and inexpensive device.

Background Art

[0002] U n li ke the majority of lithium ion batteries available today, the present devices so not present an under-voltage, over-voltage or therma l runaway risk. They present a dual mode of operation, both a high energy battery mode and power capacity supercapacitor mode a long with a burst discha rge of one (1) second or less. I n the su percapacitor mode of a device, it can store more energy than a ny other known capacitor a nd in the battery mode several of the prese nt devices store more energy for a longer period tha n most Li-ion batteries.

[0003] Si nce the advent of energy storage, humankind has been seeking a combined high power, high energy storage solution in a single device. Considerable efforts have been expended on t he development of high-performance energy-storage devices such as Lithium-ion capacitors (LICs) and Lithium-ion batteries (LI Bs). High performance energy storage devices such as superca pacitors and batteries rely on different fundamental working princi ples - bul k versus surface - electron conduction and/or ion diffusion corresponding to electrochemical versus electrostatic energy storage (1). Electric double-layer capacitors (EDLCs), which store energy through accumulation of ions on the electrodes' interface, have low energy storage capacity but very high power density. However, in hybrid capacitors (1-5) li ke LICs, despite their recent advancement, the i m bala nce in kinetics between the two electrodes still remai ns a major drawback. I n this document it is presented severa l energy storage type of devices which are neither hybrid capacitors nor lithium batteries (6-8). These devices' in their battery modes, are charged (lithinated) from the high lithium content in the solid electrolyte, the only material initially containing lithium ions. Each storage device is sequentially charged as an EDLC and battery - keeping features of a Li-S battery cell (9-19) - and then finally as an EDLC. This order is reverted during discharge. It is an autonomous switching dual functioning device, which can present a device voltage of 9 V. This device will impact a very broad spectrum of applications especially in the transportation, grid stationary, and aerospace.

[0004] I n the simplest configuration an EDLC consists of two electrodes immersed into a liquid electrolyte and separated by a membrane. Upon application of a voltage difference to the electrodes, the ions of the opposite charge of the electrolyte accumulate on the electrodes' interface in a quantity proportional to the applied voltage, forming a double layer capacitor (2). The charge storage mechanism in a typical EDLC is not Faradaic, which means that during the charge and discharge of this type of device, no charge transfer takes place across the electrolyte/electrode interface and the energy storage is of an electrostatic nature. In LICs, electrodes' carbonaceous materials may additionally exhibit chemical interactions with selected electrolytes, which involve fast and often reversible charge-transfer reactions between the carbon surface and the electrolyte ions; such processes are Faradaic. At a constant temperature and voltage, the ionic density on the carbon electrode surface is controlled by a balance between the changes in entropy and enthalpy of the system (3). The maximum voltage is generally determined by the electrochemical stability window of the selected electrolyte. Impurities and functional groups on carbon, however, may catalyze electrolyte decomposition, narrowing the operating voltage window.

[0005] Batteries on the other hand are composed by electrochemical cells. Each cell consists of positive and negative electrode separated by an electrolyte. Once the electrodes are connected externally, there are chemical reactions that occur at both electrodes, liberating electrons a nd enabling the current to be tapped by the user (4).

[0006] These facts are disclosed in order to illustrate the technical problem addressed by the present disclosure. General Description

[0007] I n an embodiment, the present disclosure relates to a supercapacitor and battery solid carbon-sulfur Li-ion based device with autonomous dual functionality which is charged from the Li-rich glassy electrolyte is herein disclosed. The devices now disclosed are safe, environmentally friendly and inexpensive. Unlike the majority of lithium ion battery chemistries available today, the devices so not present an under-voltage, over-voltage or thermal runaway risk. They present a dual mode of operation, both a high energy battery mode and power capacity supercapacitor mode along with a burst discharge of one second (1) or less. In the supercapacitor mode of a device, it can store more energy than any other known capacitor and in the battery mode several of devices stored more energy for a longer period than most Li-ion batteries.

[0008] I n an embodiment, the present disclosure relates to a supercapacitor and battery solid carbon-sulfur Li-ion based device with autonomous dual functionality and charged from the Li- rich glassy electrolyte.

[0009] An aspect of the present subject-matter is related to a layered electrochemical solid device comprising a positive electrode current collector, a positive electrode, a glass electrolyte, a negative electrode and a negative electrode current collector wherein the positive electrode current collector comprises aluminium;

the positive electrode comprises sulfur, a glass electrolyte of formula Li3-2xMxHalO and carbon;

the glass electrolyte composition comprising a compound of formula Li3-2xMxHalO wherein:

M is selected from the group consisting of boron, aluminium, magnesium, calcium, strontium, barium;

Hal is selected from the group consisting of fluoride, chloride, bromide, iodide or mixtures thereof; X is the number of moles of M and 0 < x < 0.01;

the negative electrode comprises a carbonaceous material;

the negative electrode current collector comprises copper. [0010] I n some cases, the collectors can have a predominant role. The can function as electrodes being the copper + carbon black the positive electrode and the sulfur + glass electrolyte + carbon in aluminum the negative electrode. This configuration makes the device works reversely to what was described for charge and discharge.

[0011] I n some cases, when the role of the collectors is preponderant, they may overcome the role of the electrodes, reversing the functions of the electrodes and leading to a device with inverted electrodes.

[0012] The present subject-matter relates to a layered electrochemical solid device comprising the above described layers with inverted roles.

[0013] I n an embodiment, the positive electrode may comprise 3-80 % (w/w) of sulfur, and 3-80 % (w/w) of the electrolyte composition described in any one of the previous claims and less than 20% (w/w) of a carbon; , in particular less than 10% (w/w).

[0014] I n an embodiment, the positive electrode may comprise 30-50 % (w/w) of sulfur, and 30- 50 % (w/w) of the electrolyte composition described in any one of the previous claims and less than 20% (w/w) of a carbon, in particular 10% of carbon.

[0015] I n an embodiment, the positive electrode composition may be grinded in ethanol and a slurry is prepared. This slurry can be deposited, printed or painted in the positive electrode current collector comprising aluminium.

[0016] I n an embodiment for better results, X may be 0.002, 0.005, 0.007 or 0.01.

[0017] I n an embodiment for better results, Hal may be a mixture of chloride and iodide, or chloride and bromide, or fluoride and iodide.

[0018] I n an embodiment for better results, Hal is Hal = 0.5CI + 0.51.

[0019] I n an embodiment for better results, the electrodes may be suitable to be charged with Li-ions from the electrolyte.

[0020] I n an embodiment for better results, the carbonaceous material of the negative electrode is selected from the group consisting of carbon black, graphite, graphene, carbon nanotubes, spongy carbon, carbon foam, carbon white, carbon composite, carbon paper, carbon fibres, carbon film, printed carbon, and mixtures thereof.

[0021] I n an embodiment for better results, the aluminium of the positive electrode current collector is selected from: an aluminium foam, aluminium film, aluminium foil, aluminium composite, aluminum wires, aluminum surface. [0022] I n an embodiment for better results, the copper of the negative electrode current collector is selected from: a copper foam, copper thin film, copper foil, copper composite, copper wires, copper surface, and or other engineered form of copper.

[0023] I n an embodiment for better results, the positive electrode further comprises an alcohol, an organic solvent, a polymer, or mixtures thereof. Preferably, the alcohol is ethanol, methanol, or mixtures thereof; preferably absolute methanol, absolute ethanol, or mixtures thereof.

[0024] I n an embodiment for better results, the device may further comprises a confinement, protection or wrapping immersement. Preferably, the confinement, protection or wrapping immersement is by a polymer or a resin. More preferably, the resin is an epoxy or the polymer is a water-proof polymer, or a water-resistant polymer, or a flexible polymer, or a rigid polymer, or a non-flammable polymer.

[0025] Another aspect of the present invention, disclose a capacitor comprising the layered electrochemical solid device described in the present disclosure.

[0026] A battery comprising the layered electrochemical solid device described in the present disclosure.

[0027] A dual mode battery comprising the layered electrochemical solid device described in the present disclosure.

[0028] An electrical actuator comprising the layered electrochemical solid device described in the present disclosure.

[0029] A sonar comprising the layered electrochemical solid device described in the present disclosure.

[0030] A transducer comprising the layered electrochemical solid device described in the present disclosure.

[0031] I n an embodiment, the present disclosure relates to a solid state bulk energy storage device working autonomously, simultaneously or independently as a supercapacitor and as a battery. On charge, the supercapacitor is the last mode to be fully charged and on discharge, the supercapacitor mode is the first to be discharged. The device is composed of a copper bulk collector, a negative electrode of carbon black (C) which is mostly graphite (Fig. 1A), a doped glassy electrolyte (20), U3CIO based, a positive electrode comprised of a mixture of: sulfur (Ss), a glassy electrolyte, and carbon black, deposited on an aluminum bulk collector. If some sulfur reacts with the electrolyte, during electrode preparation, it is most likely just at the surface forming an amorphous phase that cannot be distinguished from the other amorphous phases already present (glassy electrolyte and carbon black), Fig. IB. The surface dimensions of the cells' electrodes are 2.5x2.5 cm² or 2.5x3.5 cm² with a loading of 0.20-0.40 g/cm² of electrode materials and electrolyte. The sulfur loading can be 0.018-0.040 g/cm². Collectors have an extended functionality; besides being an electronic transport media, they have a support and heat dissipation functionality which is not intrinsic to the device, among other functionality. The cells have 0.15-0.35 g/cm² of electrolyte as separator. The cell's thickness is 0.20-0.35 cm. The electrodes, electrolyte and collectors were accountable to the device's weight.

[0032] I n an embodiment, the wide electrochemical window of the electrolyte (20) makes it compatible for use with a broad spectrum of battery and supercapacitor electrodes. The Li-rich transport characteristics of the electrolyte permit enhanced cell component kinetics and increased life cycle. Moreover, the battery mode is lithinated from the electrolyte and in the sulfurbased electrode the Li-ions do not cross the electrode's surface allowing for a new set of electrode com binations such as the carbon-sulfur pair presented herein. The open circuit's voltage at the time of cell fabrication, is lower than 0.6 V permitting for extremely safe transportation and storage. Consequently, the device can be charged at the destination as battery or/and supercapacitor.

[0033] I n an embodiment, two galvanostatic charging processes for the carbon(C)/electrolyte/sulfurbased(S) - device 0 are shown in Fig. 2A, at a current of 0.6 mA and 1.2 mA. The EDLCs within device 0@b begin to charge at Δν = 1 V achieving a maximum capacity of 5.8 mAh. The capacitor only starts charging at 1 V due to the resistance difference between the positive and negative electrodes including the electrolyte's internal resistance which will be overcome when the EDLCs start to charge as presented in Fig. 2B(1) after having discharged in a configuration like the one in Fig. 2B(4), as wi ll be detailed herein. Figure 2B shows the current explanation for the physical and chemical processes in the device during galva nostatic charge and discharge. In Fig. 2B(1), at the carbon electrode and after the electrons conduction and accumulation at the surface, an EDLC(a) will be formed with the separator electrolyte's Li-ions that accumulate at the interface. This process leaves Li-ions holes (vacancies) on the opposite surface of the separator electrolyte (at the positive electrode interface), which correspond to a negative net charge. At the sulfurbased electrode, 46 wt of the electrode is comprised by the lithium-rich electrolyte whose Li-ions accumulate at the surface. With the Li-ion vacancies within the separator electrolyte, the latter constitute the EDLC(b) at the positive electrode's interface. At the interface electrode/collector another EDLC(c) forms from the Li-ion vacancies on the sulfurbased electrode and the positive ions Al³⁺ at the surface of the Al collector. In Fig. 2B(2), the Li-ions of the electrolyte at the carbon electrode initiate diffusion into the electrode. I n the graph of Fig. 2B this phenomenon can be observed above 1.26 V, the voltage at which the Li-ion battery mode begins to charge. This mode of charge is also visible for device 0@c, above 1.6 V presented in Fig. 2A. The shape of the charge curve for this mode is actually very similar to a Li-S battery correspondent charge curve (14, 17). The inbound ions within the carbon electrode will be reduced by the electrons and LiC6 will be formed. Device 0@ b is fully charged at 22.0 mAh (Fig. 2A and 2B) in its battery mode. The capacity of this mode is 16.2 mAh corresponding to a capacity of 324 mAh/g_carbon(-) (87% of the theoretical capacity of the graphite). The carbon electrode, which is composed of amorphous carbon and graphite, determines the battery's maximum capacity. During battery mode charge, the EDLCs(b,c) that were formed at the positive electrode are accountable for the voltage difference of 0.6-1.1 V over the battery potential. A C-S battery is theoretically charged at 2.1-2.5 V (a Li-S battery is fully charged at 2.4-2.8 V (17)); this device's battery mode will be fully charged at 3.2 V which is in the range of 2.7-3.6 V as presented in 0@b and 0@c. In Fig. 2B(3), after lithium and Li-ion positive charge accumulation saturation at the negative electrode's surface, the Li-ions diffuse to the positive electrode electrolyte interface forming with Li-ion holes at the positive electrode's interface a new EDLC(b). In fact, during the Li-ion diffusion towards the positive electrode the electrolyte's internal resistance to charge transfer is overcome. This resistance can vary depending on the device's cycling. I n Fig. 2B(4), it is presented an explanation for the device's discharge process. The electrolyte's Li-ions in the positive electrode EDLC(c) will receive the electrons transported via external circuit from the negative electrode which will reduce and react with sulfur, leaving vacancies at the inner surface of the positive electrode. When the positive electrode stops producing L12S, 4 to 21wt% (depending on the device) of the positive electrode's sulfur will have been actively used during battery mode discharge. A EDLC(b) will be formed at the su lfurbased electrode's interface with the Li-ions of the separator electrolyte and the vacancies of the electrode's electrolyte. On the negative electrode's side, oxidized carbon and/or the Li-ions that eventually remained after battery discharge will form another EDLC(a) with the Li-ions vacancies in the electrolyte (corresponding to a negative net charge).

[0034] I n Fig. 2A and 2C, it is observed that following the EDLCs burst discharge at Voc, the battery mode will start discharging at 2.89 V and after 19 h the device reaches a steady state at 1.4-1.2 V that will remain for more than 4 days and which is likely to be due to the formation of new EDLCs as shown in Fig. 2B(4). This extra capacity will be included in the battery mode calculations in this work for simplicity and to distinctively mark two discharging moments: one that takes 1 s and the other that can take up to days to discharge. Figure 2D presents the galvanostatic charge/discharge of device 0@a at ±1.2 mA as a function of the capacity. While discharging, the device quickly changes its polarity and starts charging after discharging. The total electrostatic energy for charge is 79 mWh and for discharge is 84 mWh, indicating that the device starts to charge after discharge. The process in which the EDLCs are charged during discharge is exactly the reverse in terms of polarity but very similar to the one described in Fig. 2B(3), as shown in Fig. 2B(5). The three capacitors in Fig. 2B(5) were observed in a EIS experiment with device 1 Fig. 5. In Fig. 2E to 2G, three different galvanostatic charge/discharge cycles of device 1 can be analyzed. In Fig. 2E the battery mode in device 1 is discharged at a negative voltage after initial burst at open circuit voltage. The internal resistance to charge transfer is similar to that observed on charge for both devices 0@a and l@a (110 char e vs. 108 Qdischarge for 0@a, Fig. 2D, and 42 Q_charge/discharge for l@a Fig. 2E). In Fig. 2F, it is observed that the saturation voltage of the EDLCs during the "discharge" at a negative constant current is very similar to that of charge. The latter is expected, since this voltage is dependent on the electrochemical window of stability of the electrolyte and of the impurities as mentioned previously.

[0035] I n an embodiment, Fig. 2G and Fig. 6 present other charge/discharge cycles of device 1. In Fig. 2G the device l@d charges as a capacitor to 3.8 V in less than 10 s and to 5 V in 90 s. Discharge took place at I « 0 mA. I n this experiment, it may be observed that the device did not discharge as a battery. A steady state was achieved with EDLCs formation corresponding to Fig 2B(4). After 14 h, the cell's voltage was still 2.60 V. The Li-S battery characteristic discharge curve could not be observed conversely to what was observed in previous experiments. The ability to keep the battery mode charged seems to be inversely proportional to the percentage of Li-ions of the electrolyte in the positive electrode which is effectively used in battery mode discharge and which varies from 6%-device 1 to 33%-device 3. In Fig. 3A two consecutive charging processes of device 0 and 1 are shown (more in Fig. 6). It can be observed how the internal resistance drops from experiment a to b in both devices. After sufficient conditioning, not only does the electrolyte's internal resistance drop, but also the EDLCs charge transfer resistance. The EDLCs load up to 7.5 V in experiment b of both devices. Fig. 3B presents the charging process of device 2 during its first charge. The process is very similar to the charges shown for device 0 and 1. Nonetheless, the EDLCs maximum tolerance voltage is 9.0 V and the battery mode is fully charged at 4.0 V. Fig. 3C presents a zoom of the discharge of device 2@ b. It discharges from 9.1 V to 3.0 V in 1 s and subsequently starts discharging a remanent the battery mode charged during experiment a (Voc prior to experiment b was 1.1 V). Fig. 3D presents the charge of device 4@c. The device does not seem to charge as a battery and immediately achieves 4.26 V. The capacitance shown during experiment c is very high, achieving 622 F. It is highlighted that the energy stored is 772 Wh/kg_ceii but the device could be kept charging since the correspondent voltage was 6 V. Fig. 3E presents the open circuit discharge of the device [email protected] burst discharge takes 1 s or less and the device discharges almost completely (from 6 to 0.8 V) indicating that the device just performed in EDLC mode. The elevated value of energy stored and displaced charges facilitated full discharge at burst since highly dynamic processes were promoted. Fig. 3F shows the charge of device 4@d at a constant voltage of 5 V. The resistance can be calculated and is of the order of 2.2-2.75 kΩ. During the first part of the measurement, the resistance dropped from 2.5 to 2.1 kQ indicating self-organization leading to optimization of the cell, despite having four months of shelf-life and more than 300 cycles. The charge is extremely stable and the current never dropped to more than 80 % of the initial current which indicates that the cell could have been further charged. Actually, the capacitance achieved in experiment 4@c was 622 F indicating that experiment 4@d could have been substantially extended. Fig. 3G presents the schematic representation of the equivalent circuit of the nearly discharged device corresponding to Fig. 2B(4). Fig. 3H and Fig. 8 present a comparative analysis of the conditioning process of device 0 through the variation of the capacitances and resistances measured by EIS at fabrication voltage. The charge transfer resistance of the EDLC(a) at the carbon electrode does not improve considerably with cycling. The capacitance of the latter EDLC(a) is of the order of the nF. At the positive electrode the EDLCs(b,c) capacitance is of the order of the mF after conditioning, which is six orders of magnitude higher than the corresponding of the negative electrode. However, during charge, the EDLC(a) increases its capacitance considerably and attains similar EDLCs(b,c) capacitance. The capacitance of the EDLC(b) will increase considerably with cycling (0.12 nF @3 days and no cycles, and 0.61mF @48 days and 80 galvanostatic cycles). The capacitor formed by the Li-ions of the electrolyte in the sulfurbased electrode and the electrons in the collector is not observed in device 0 in Fig. 3H but an EDLCs(c) is observed in device 1 in Fig. 5. Fig. 31 shows charge/discharge cycles performed on device 1 after experiments a to d. In the first cycles, the battery mode can be observed, especially at discharge. Alternatively, the last cycles only show evidence that the device only performs in capacitor mode. [0036] I n an embodiment, Fig. 4A shows a cyclic voltammetry curve for device 0 at 1 mV/s (other CVs for device 0 and 4 in Fig. 7 and 8). This device shows the features of a Li-S battery between - 2.24 and 3.1 V (12, 13, 16). The charge of the carbon electrode at 3.1 V is observed as well as the discharge of the sulfur electrode at inverted polarity (-2.24 V). Outside this range, the features of a capacitor immerge. The pseudo-capacitance due to Faradic interactions at the carbon electrode are remarkable for a voltage between 4.2-6.2 V. The capacitance reaches 110 F/g_carbon(-) and 160 F/gcarbon(+). There are no visible Faradic interactions at the sulfu rbased electrode which is expected since the carbon(+) does not appear to play an active role and the Li-ions never cross this electrode. It should be highlighted that the hysteresis is especially reduced at high AV/At rates (Fig. 7 and 8). It is concluded that the reduced power loss in the capacitor mode is attributed to a small dielectric hysteresis and dielectric leak. If the - battery and capacitor mode - of an autonomous device are considered independently, then for example the EDLC in device 3 performs with a power density of 240 W/cm³ (157,000 W/kg) and an energy density of 0.0666 Wh/cm³ (56.9 Wh/kg) and the battery mode with power density of 0.0378 W/cm³ (32.3 W/kg) and energy density of 0.113 Wh/cm³ (96.9 Wh/kg) as represented on the Ragone plot in Fig. 4B. It is highlighted the performance of the EDLC mode of device 4@c. The supercapacitor mode of these devices can store more energy than any other known capacitor and the battery mode of most devices can store energy for more time than Li-ion batteries. For simplicity, it is considered the device to be in battery mode after the discharge burst although the EDLCs that charge in this mode contribute considerably to its discharge time, as previously discussed. Fig. 4C shows how the capacitor's capacitance varies as a function of the capacity in device l@a. The first part of this capacitance increase is due to battery mode charge and the second due to the formation of EDLCs. A total maximum capacity of 1,650 mAh/g_carbon(-) is achieved. A cell capacity of this magnitude is not due to the battery's electrochemistry (since graphite's theoretical capacity is 372 mAh/g) . In the battery mode the maximum capacity achieved is 364 mAh/g_carbon(-) (98% of the theoretical capacity); with the remaining capacity being attributed to the EDLCs. Conversely, sulfur is under-utilized since only 104 mAh/g_SUifur of its theoretical maximum capacity of 1,670 mAh/g are used. Moreover, sulfur will only have an active role at the battery mode level of device 1 corresponding to «6% of its maximum capacity, which is in agreement with the overall battery reaction (the percentage of the sulfur actively used was 4-8% for devices 0, 1, 2, and 4 and 21% for device 3). The capacitance at the negative electrode of device l@a will increase to a maximum of 674 = 1,550 - 876 F/g_carbon(-) after battery charge and during Li-ion accumulation at the negative electrode. The capacitance corresponding to the EDLCs(b,c) Fig 2B(3), is gained after overcoming the internal resistance of the electrolyte. The cell's capacitance reached a maximum of 90 F/gceii and 3,000 F/g_carbon(-). Fig. 4D provides insight into the charging mechanism. Up to 1.26 V the EDLCs form as suggested in Fig. 2B(1) and the maximum capacitance is 43.8 F. Then the battery starts to charge Fig. 2B(2) and the capacitance drops to 20.4 F which corresponds to approximately half of the previous capacitance due to a half drop in charge accumulated at the equivalent capacitor for the same voltage. At the cell level, the capacitance actually decreases due to a sudden voltage increase, at approximately constant charge, owing to charge diffusion towards the negative electrode. Then the capacitance will increase again due to battery mode charge. During the latter charge, the EDLCs(b,c) remain charged. When C = 32.6 F, the battery is charged. The capacitance will increase again up to 39.4 F due to charge accumulation at the negative electrode (the voltage remains approximately constant), moment at which the negative electrode becomes a LIC electrode. The Li-ions reverse direction when charge accumulation at the negative electrode saturates and reversely charged EDLCs form at the surfaces. Prior to this latter inversion of Li-ion diffusion direction, the capacitance step-increases due to a drop of voltage corresponding to the internal resistance to charge transfer. The maximum capacitance C = 52.5 F is reached at 4.0 V (which corresponds to all the capacitors charged, approx. 40.0 F, plus the battery contribution, 12.5 F. Then the capacitance starts decreasing. It drops down to 30.0 F at V = 6.9 V. This drop of capacitance is eventually due to Faradic interactions at the carbon electrode, which result in capacitor's discharge. This effect is also observed in CV of Fig. 4A during charge for 5.00 V < Voltage < 6.45 V. Fig. 4E shows the behavior of the capacitance with the voltage rate (AV/At). For more capacitance analysis in devices 0 and 3, Fig. 9.

[0037] I n an embodiment, it is disclosed devices that are safe, environmentally friendly and inexpensive. The present devices are both supercapacitors and batteries. The switching between the two modes on charge and discharge is autonomous. The EDLCs important discharge takes place in 1 s or less. It is likely that other EDLCs are formed at discharge which proportionate a delay of the battery mode discharge. Moreover, it was observed that it is possible to charge the devices during galvanostatic discharge. The present devices, working in battery mode, are uniquely lithinated from the Li present in the electrolyte; in effect, the sulfur at the positive electrode will only react with the Li-ions of the electrode's electrolyte protecting the electrodes interface and avoiding polysulfide shuttle. The Li-ions never cross this latter surface even during battery mode discharge. It was never observed a substantial variation of the device's temperature while running experiments (a maximum of 0.5 °C at 9V). The charge transfer resistance of the EDLCs at the positive electrode decreases considerably with cycling, possibly revealing self-assembling and self-healing at the nanoscale. Several devices performed more than 100 cycles and sustained a shelf life of three months while still performing as battery, besides supercapacitor. In fact, these devices benefit considerably with conditioning. It will be possible to tailor these devices by changing relative compositions, and by optimizing each component of the device. The capacitor or battery mode properties will depend on the previous parameters and therefore will be adapted in view of an application.

[0038] I n an embodiment, the devices 0-4 previously discussed, are of the same family here described and only differ in weight, amount and thickness of positive, negative electrodes/collectors and electrolyte and or surface area.

[0039] Throughout the description and claims the word "comprise" and variations of the word, are not intended to exclude other technical features, additives, com ponents, or steps. Additional objectives, advantages and features of the solution will become apparent to those skilled in the art upon examination of the description or may be learned by practice of the solution.

Brief Description of the Drawings

[0040] The following figures provide preferred embodiments for illustrating the description and should not be seen as limiting the scope of present disclosure.

[0041] Figure 1: X-ray diffraction (XRD) patterns of the electrodes prior to device assembly. (A) The carbon black negative electrode showing amorphous carbon and graphite. (B) The sulfurbased positive electrode showing an amorphous phase (the electrolyte and carbon), and textured crystalline sulfur. The experiment was performed in order to mitigate the amorphous component diffuse scattering.

[0042] Figure 2: Galvanostatic charge/discharge characterization cycles for devices 0 and 1. (A) Device 0 during experiments b and c. (B) Simplified schematic representation of the processes occurring during galvanostatic charge/discharge of the present devices. The E represents the electric field and the arrow above it its direction. (C) Zoom of the first seconds of the discharge of device 0 during experiment c. (D) Charge/discharge of device 0, during experiment a. (E) Charge/discharge of device 1 during experiment a. Burst discharge took place at V₀c (F) Charge/discharge of device 1 during experi ment c. (G) Cha rge/discharge of device 1 during experi ment d.

[0043] Figure 3: Cha rge/discharge characterization cycles of devices 0, 1, 2 a nd 4. (A) Charges of devices 0 a nd 1. Evol ution of electrolyte's charge tra nsfer resista nce, j, during consecutive experi ments. (B) First cha rge of device 2. (C) Zoom of the discharge of device 2@ b showing EDLC burst a nd battery mode at V_oc discha rge. (D) Cha rge of device 4 during experi ment c. Ca pacita nce evolution during charge. (E) Discharge of device 4 during experiment c. (F) Maximum capacity determi nation for device 4 during charge at constant voltage (5 V) in experiment d. (G) Schematic representation of the equiva lent circuit after open ci rcuit's discharge correspondent to Fig. 2B(4). Ra = 2R_e + Ri (see Methods). (H) Electrochemical Impedance Spectroscopy (EIS) of device 0 showing EDLCs ca pacitances and internal resistances evolution after 13 days and 60 cycles: V_oc@ 13days = 0.30 V vs. Li/Li⁺ and Rn = 35.6 Ω, R_c = 1,179 Ω, C_c = 0.10 nF, R_s = 748 Ω, C_s = 0.90 m F. After 48 days and 80 cycles: V_oc@48days = 0.32 V vs. Li/Li⁺ and Rn = 70.4 Ω, R_c = 136 Ω, Cc = 0.14 nF, Rs - 1704 Ω, Cs = 0.61 mF. (I) Charge/discha rge cycles of device 1 during experiment e.

[0044] Figure 4: Electrochemical and physical characterizations of devices 0, 1, 2, 3 and 4. (A) Cyclic volta m metry (CV) of device 0 during cha rge and discharge at 1 mV/s. (B) Ragone plot (27) with data from (28-30). The com parison of the energy and power density of MPG -MSCs with TG- MSCs, MPG-SSCs (28), com mercia l ly applied electrolytic capacitors (23), lithium thin-fi lm batteries (30), Panasonic Li-ion battery (30), and devices 0, 1, 2, 3, and 4 ta king into consideration two modes of the sa me device: EDLC and battery a nd just EDLC for device 4@c. (C) Capacitance in Farad (F) as a function of the ca pacity in (mAh) during charge of device 1 in experi ment a. (D) Ca pacita nce and cell voltage as a function of time for device 0 in experiment b. (E) Capacitance's dependency on the voltage rate (Δν/Δΐ) for device 0.

[0045] Figure 5: Electrochemica l i mpedance spectroscopy (EIS) of device 0 after 3, 13 and 48 days of fabrication and device 1 after 5 days of fabrication. (A) EIS of device 0@3days and before cycling, showing: Rn = 47.7 Ω, R_c = 122 Ω, C_c = 0.82xl0 ⁹ F, R = 32.1xl0⁶ Ω, C

11.5xl0⁹ F (V_oc@ 3days = 0.42 V vs. Li/Li⁺) . (B) zoom of a in com parison with the EIS obtained after 48 days, showing the semi-circle characteristic of the EDLC at the carbon negative electrode interface in parallel with its internal resistance. The capacitance of the ca rbon-electrolyte EDLC and its associated interna l resistance do not improve considera bly with shelf time and cycling. (C) EIS of device 0(5⁾ 13 days and 60 cycles and C chargi ng rates (0.01C to 0.04C of the device a nd 0.04C to 0.15C of the battery mode) showing: Ra = 35.6 Ω, R_c = 1179 Ω, C_c = O.lOxlO^-9 F, Rs.interface = 748 Ω, Cs.interface = 0.90xl0 ³ F and @48 days and 80 cycles at different C charging rates (0.01C to 0.04C of the device and 0.04C to 0.15C of the battery mode) showing: Ra = 70.4 Ω, Rc = 136 Ω, C_c = 0.14xl0-⁹ F, Rs .interface - 1704 Ω, Cs .interface - 0.61xl0^"3 F (Voc@13 days = 0.30 V vs. Li/Li⁺ and Voc@48 days = 0.32 V vs. Li/Li⁺). The capacitance and resistance of the EDLCs at the sulfur electrode do not improve much from the 13^th to 48^th day and with cycling, but they improve considerably from the 3^rd day, eventually due to cycling conditioning. (D) EIS of device 1 after 5 shelf days and after 52 galvanostatic cycles at C-charge and discharge rate (0.02C of the device and 0.08C of the battery mode), showing three semi-circles corresponding to three capacitors in serial, possibly the configuration in Fig. 2b(5): Ra = 25.4 Ω, Rc = 8.7 Ω, Cc = 43.2xl0⁹ F, Rs.interface = 1408 Ω, Cs .interface = 0.27xl0-³ F, Rs.in ner space — 1418 Ω, Cs.inner space = 0.78X10 ³ F (Voc@5days = -0.07 V vs. LiVLi ) .

[0046] Figure 6: Galvanostatic charges/discharges of device 0, 1 and 3. (A) Charges/discharges 0@e and 0@f were performed in the same day. The device 0@f discharges the EDLCs in Is (AV = 5.13 V). (B) The device l@f discharges the EDLCs in Is or less (AV = 5.15 V). (C) The device 3@g discharges the EDLCs in Is or less (AV = 6.75 V).

[0047] Figure 7: Cyclic voltammetry (CV) for device 0. (A) Charge and discharge at 500 mV/s. (B) Charge and discharge at 500 mV/s. (C) Charge and discharge at 100 mV/s. (D) Charge at 50 mV/s. (E) Charge and discharge at 10 mV/s.

[0048] Figure 8: Cyclic voltammetry for device 4. (A) Charge and discharge at 200 mV/s. (B) Charge at 50 mV/s.

[0049] Figure 9: Galvanostatic charges of devices 0@c and 3@a. (A) Device 0's capacitance due to its battery mode charging is 12.9 F. The maximum capacitance in this measurement is 32 F, 16 F/gceii and 535 F/g_carbon(-). (B) The device 3's capacitance due to its battery mode is approx. 47 F. The maximum capacitance in this measurement is 132 F, 90 F/g_ceii and 2,880 F/g_arbon(-)-

Detailed Description

[0050] The present disclosure relates to the development layered electrochemical solid devices, in particular to the development of a new device; a supercapacitor and or a battery solid carbon- sulfur Li-ion glassy electrolyte based device with autonomous dual functionality comprising a safe, environmentally friendly and inexpensive device. [0051] The present subject-matter relates to a layered electrochemical solid device comprising a positive electrode current collector, a positive electrode, a glass electrolyte, a negative electrode and a negative electrode current collector wherein

the positive electrode current collector comprises aluminium;

the positive electrode comprises sulfur, glass electrolyte and carbon;

the electrolyte composition comprises a compound of formula Li3-2xMxHalO wherein: is selected from the group consisting of boron, aluminium, magnesium, calcium, strontium, barium;

the negative electrode comprises a carbonaceous material;

the negative electrode current collector comprises copper.

[0052] The present subject-matter relates to a layered electrochemical solid device comprising the described layers with inverted roles.

[0053] I n an embodiment of synthesis of the glassy electrolyte Li3-2*o.oo5Bao.oosCIO was prepared from the commercial precursors LiCI (Merck > 99% for analysis), LiOH (Alfa Aesar 98.0%) and Ba(OH)₂.8H₂0 (Merck 98.5%) as described in (20). After synthesis the electrolyte was heated to 250 °C for one hour and then cooled down, avoiding contamination with water from the air's moisture. A slurry was then prepared by grinding the electrolyte in ethanol (Merck 99.9% absolute for analysis). The slurry was protected in an Ar atmosphere.

[0054] I n an embodiment the positive electrodes were prepared by adding sulfur, Ss, (Alfa Aesar Powder 99.9995% Puratronic) to the above prepared electrolyte (before mixing it with ethanol) and to carbon black (TIMCAL super C65) in a 47:46:7 weight ratio. The carbon black's XRD (Fig. la Extended Data) shows the presence of graphite and amorphous carbon, probably denoting grains with an external crystalline layer and an amorphous inner phase. This mixture was grinded in ethanol (Merck 99.9% absolute for analysis). There were no prior perceptible reactions between the sulfur, the electrolyte and the graphite as presented in the XRD in Fig. lb. The slurry was deposited on an Aluminum (Al) collector foil (Alfa Aesar Foil 99.45% 0.025 mm thick) with 2.50x2.50 cm² or 2.50x3.45 cm² and let dry at approximately 100 °C for 30 min (corresponding to 40-80 mg/cm² of positive electrode). The electrolyte's slurry was deposited on the top of the positive electrode and let dry for approximately 100 °C for 30 min (corresponding to 100-300 mg/cm² of electrolyte). [0055] I n an embodiment, the negative electrode was prepared by mixing carbon black from TIMCAL super C65 with ethanol (Merck 99.9% absolute for analysis) in a 12:88 weight ratio. The resulting slurry was deposited on a copper (Cu) collector foil (Alfa Aesar Foil 99.8% 0.025 mm thick) and let dry for about 10-20 min at 100 °C (corresponding to 8-14 mg/cm² of carbon). The device is then prepared by matching the two collectors resulting in a layered device with Al collector/positive electrode/electrolyte/negative electrode/Cu collector. The resulting active devices were 0.20-0.35 cm thick. The device was then hermetically sealed in a moisture and oxygen free container. Collectors' terminals were left with external access.

[0056] I n embodiment X-ray diffraction measurements the samples of the positive and negative electrodes and electrolyte were submitted to X-ray Diffraction (XRD) in a Panalytical instrument, using CuKa radiation (A = 1.54 A) with 0.2° 2& steps and 0.5 s dwelling time, to determine the amount of the product present in the sample.

[0057] Electrochemical measurements. I n an embodiment, Galvanostatic cycling, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were performed using a SP240 potentiostat (Bio-Logic, France). Galvanostatic cycling was performed at 0.2-1.8 mA/g and between the potential limits of -10 V to 10 V versus Li/Li⁺ and Li⁺/Li. The CV was performed using scan rates that ranged from 1 mV/s to 500 mV/s. The EIS was performed at open circuit voltage, with a sinus amplitude of 10 mV, and frequencies that ranged from 100 mHz to 5 MHz.

[0058] Open circuit voltages (at fabrication, with battery mode charged and after discharge) were additionally measured with commercial multimeters.

[0059] Conductivity, Resistance and Permittivity calculations. I n an embodiment, The ionic conductivity, resistance and permittivity of the crystalline and glassy electrolyte was measured using gold block electrodes and calculated using the equivalent circuits described in (20).

[0060] The disclosure should not be seen in any way restricted to the embodiments described and a person with ordinary skill in the art will foresee many possibilities to modifications thereof.

[0061] The above described embodiments are combinable. The following claims further set out particular embodiments of the disclosure.

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Claims

C L A I M S

1. A layered electrochemical solid device comprising a positive electrode current collector, a positive electrode, a glass electrolyte, a negative electrode and a negative electrode current collector wherein

the positive electrode current collector comprises aluminium;

the positive electrode comprises sulfur, a glass electrolyte of formula Li3-2xM_xHalO and carbon;

the glass electrolyte composition comprising a compound of formula Li3-2xM_xHalO wherein:

the negative electrode comprises a carbonaceous material;

the negative electrode current collector comprises copper.

2. The layered electrochemical device according to any of the previous claim wherein the positive electrode comprises 3-80 % (w/w) of sulfur, and 3-80 % (w/w) of the electrolyte composition described in any one of the previous claims and less than 20% (w/w) of a carbon; in particular less than 10% (w/w).

3. The layered electrochemical device according to any of the previous claim wherein the positive electrode comprises 30-50 % (w/w) of sulfur, and 30-50 % (w/w) of the electrolyte composition described in any one of the previous claims and less than 20% (w/w) of a carbon, in particular 10% of carbon.

4. The layered electrochemical device according to any of the previous claims wherein X is 0.002, 0.005, 0.007 or 0.01.

5. The layered electrochemical device according to any of the previous claims wherein Hal is a mixture of chloride and iodide, or chloride and bromide, or fluoride and iodide.

6. The layered electrochemical device according to any of the previous claims wherein Hal is Hal = 0.5CI + 0.51.

7. The layered electrochemical device according to any of the previous claims wherein the electrodes are suitable to be charged with Li-ions from the electrolyte.

8. The layered electrochemical device according to the previous claims wherein the carbonaceous material of the negative electrode is selected from the group consisting of carbon black, graphite, graphene, carbon nanotubes, spongy carbon, carbon foam, carbon white, carbon composite, carbon paper, carbon fibres, carbon film, printed carbon, and mixtures thereof.

9. The layered electrochemical device according to any of the previous claims wherein the aluminium of the positive electrode current collector is selected from : an aluminium foam, aluminium film, aluminium foil, aluminium composite, aluminium wires, aluminium surface.

10. The layered electrochemical device according to any of the previous claims wherein the copper of the negative electrode current collector is selected from: a copper foam, copper thin film, copper foil, copper composite, copper wires, copper surface, and or other engineered form of copper.

11. The layered electrochemical device according to any of the previous claims wherein the positive electrode further comprises an alcohol, an organic solvent, a polymer, or mixtures thereof.

12. The layered electrochemical device according to the previous claim wherein the alcohol is ethanol, methanol, or mixtures thereof; preferably absolute methanol, absolute ethanol, or mixtures thereof.

13. The layered electrochemical device according to any of the previous claims wherein said device further comprises a confinement, protection or wrapping immersement.

14. The layered electrochemical device according to the previous claim wherein the confinement, protection or wrapping immersement is by a polymer or a resin.

15. The layered electrochemical device according to the previous claim wherein the resin is an epoxy or the polymer is a water-proof polymer, or a water-resistant polymer, or a flexible polymer, or a rigid polymer, or a non-flammable polymer.

16. A capacitor comprising the layered electrochemical solid device described in any one of the previous claims.

17. A battery comprising the layered electrochemical solid device described in any one of the previous claims.

18. A dual mode battery comprising the layered electrochemical solid device described in any one of the previous claims.

19. An electrical actuator comprising the layered solid electrochemical device described in any one of the previous claims.

20. A sonar comprising the layered electrochemical solid device described in any one of the previous claims.

21. A transducer comprising the layered electrochemical solid device described in any one of the previous claims.