Hybrid power supply circuit and use of a hybrid power supply circuit

Abstract

Hybrid Energy Supply Circuit (HEVS), encompassing - a first energy storage device (ES1) and - a second energy storage device (ES2) - the first (ES1) and second (ES2) energy storage units are combined in one module and electrically interconnected, - the first energy storage device (ES1) is a solid-state battery and - the first energy storage device (ES1) and the second energy storage device (ES2) are formed from SMD-compatible individual components that are soldered directly together.

Description

[0001] The invention relates to a hybrid power supply for electrical circuits that have specific requirements for an energy source.

[0002] Modern electronic components are designed to be as small as possible and to offer an ever-increasing range of electrical functions. To achieve this, they require energy sources that provide a highly stable supply voltage, withstand a high number of cycles without degradation, and exhibit short response times to charging and discharging pulses.

[0003] It is possible to power electrical devices with batteries or accumulators. Batteries and accumulators are well-suited for applications with continuous load current operation. Batteries are problematic in applications with pulsed additional load and / or irregular charging cycles.

[0004] From the article “Rechargeable Solid State Bare Die Batteries”, Cymbet Corporation, datasheet: “EnerChipBare Die” describes electrical circuits with a solid-state battery.

[0005] US patent 2014 / 0181540A1 describes energy sources for portable electronic systems consisting of a capacitor and an accumulator.

[0006] Hybrid energy storage systems with a parallel connection of two energy sources are known from WO 2003 / 088 373 A2.

[0007] Solid-state accumulators and corresponding manufacturing processes are known from WO 2016 / 176 491 A1.

[0008] Electrical components with two energy storage devices are known from US patent 6 805 998 B2.

[0009] From DE 100 64 445 A1 a multilayer component is known in which two capacitors are arranged one above the other and are produced by joint sintering.

[0010] In the so-called Internet of Things (IoT), a multitude of different electrical devices are intended to communicate with each other, preferably via wireless connections. Continuous communication is not necessary. The use of batteries is particularly problematic in devices where sensors operate continuously and communication with an external environment occurs at regular or irregular intervals. If the batteries are designed to adequately cover the continuous load, power supply becomes problematic when additional loads are present. Conversely, if a battery is designed to constantly handle additional loads, it is oversized most of the time.

[0011] Therefore, there is a desire for a power supply circuit that meets the above-mentioned specifications.

[0012] The independent claim specifies a hybrid power supply circuit. Dependent claims describe advantageous embodiments of the invention.

[0013] The hybrid energy supply circuit comprises a first energy storage device and a second energy storage device. The first and second energy storage devices are combined in a single module and electrically connected. The first energy storage device is a solid-state battery.

[0014] The combination of two different energy storage devices, one of which is a solid-state battery, makes it possible to operate electrical devices with a continuous load and at the same time provide a power supply with sufficient power for short power peaks, e.g. pulsed additional loads.

[0015] The use of a solid-state battery as the first energy storage device capable of handling a continuous load offers numerous advantages: Solid-state batteries can be manufactured in almost any shape. They have a high energy density and can therefore be produced in small dimensions. Such batteries are relatively insensitive to damage and electrolyte loss, as they do not contain a liquid electrolyte. Furthermore, solid-state batteries can be made from materials compatible with the manufacturing processes used for other circuit components.

[0016] Especially in comparison with conventional hybrid systems consisting of batteries or conventional accumulators on the one hand and capacitors on the other, the hybrid power supply circuit described here represents an improvement.

[0017] It is therefore possible for the second energy storage device to be a capacitor. The second energy storage device can be selected from a ceramic capacitor, a multilayer capacitor, a multilayer ceramic capacitor, or a double-layer capacitor.

[0018] Such capacitors also have a high energy density and allow the continuation of the ongoing trend towards the miniaturization of electrical devices.

[0019] Solid-state batteries provide a voltage-stable energy source. Capacitors are characterized by high cycle stability and a fast response to charging and discharging pulses.

[0020] The described hybrid power supply circuit is maintenance-neutral, meaning it requires no more maintenance than conventional hybrid power supply circuits. Furthermore, it allows for a smaller design, and the elimination of a liquid electrolyte improves its lifespan and reliability.

[0021] It is possible that the power supply circuit also includes an ASIC chip (ASIC = application-specific integrated circuit) for controlling or regulating a charging or discharging process.

[0022] Such ASICs can be optimized for specific parameters, such as energy efficiency, for a particular application. This type of circuit makes it possible to protect the battery from deep discharge or overcharging.

[0023] The circuit in the ASIC chip is electrically coupled to the first energy storage device and the second energy storage device.

[0024] The first and second energy storage devices are also electrically coupled. It is conceivable that the two energy storage devices are connected in series or – preferably – in parallel.

[0025] Both energy storage devices can be connected via a first connection and a second connection, through which the hybrid energy supply circuit can be charged and through which the energy supply circuit can deliver electrical energy to a circuit environment.

[0026] According to the invention, the first energy storage device is designed as a first SMD component (SMD = surface-mounted device). The second energy storage device is designed as a second SMD component. The first and second SMD components can be arranged one above the other or side by side and interconnected. Not according to the invention, the first energy storage device and the second energy storage device are manufactured together monolithically as a multilayer system in a multilayer process.

[0027] A multilayer system consists of numerous layers of different materials arranged on top of each other. Dielectric and electrically conductive layers can alternate within this system.

[0028] A capacitive element, for example, can have a multitude of electrode layers in metallization planes with dielectric layers arranged between them. Adjacent electrode layers arranged one above the other are alternately connected to one of two terminal electrodes.

[0029] Similarly, a solid-state battery can also have superimposed layers of structured electrode layers and electrolyte layers arranged in between.

[0030] Manufacturing processes for multilayer systems, e.g. HTCC layer stacks (HTCC = High temperature cofire ceramics) or LTCC multilayer systems (LTCC = Low temperature cofire ceramics), are produced by appropriate known and well-controlled multilayer processes.

[0031] It is possible to find a set of materials with which, on the one hand, a multilayer capacitor and, on the other hand, a solid-state accumulator can be manufactured. The materials are preferably selected to be compatible with processes for manufacturing such multilayer components.

[0032] It was therefore discovered that multilayer ceramic substrates can be produced that contain both capacitors and solid-state batteries. This allows for extremely high energy and power densities.

[0033] However, the stacked arrangement of SMD components in the form of capacitors and solid-state batteries also allows for extremely high energy and power density.

[0034] It is preferable if the solid-state battery is reflow-compatible. This means that the solid-state battery is thermally stable enough to withstand the temperatures during a reflow soldering process without being damaged.

[0035] It is possible, e.g. as an alternative to or in addition to an element implemented in a multilayer structure, that the second energy storage device is a normal ceramic capacitor, a MegaCap type capacitor (designation of the company TDK), a CeraLink type capacitor, in particular of the Ultrabar type (designations of the company EPCOS), or a capacitor of another UltraCap or SuperCap type, or a ceramic capacitor with a particularly high capacitance density.

[0036] It is possible that the power supply circuit also includes a varistor and / or a diode, e.g. a Zener diode, to limit a voltage to a minimum value (e.g. during discharge) or a maximum value (e.g. during charging).

[0037] A varistor is a circuit element with an electrical resistance that depends on the applied voltage. The electrical resistance decreases as the applied voltage increases.

[0038] The varistor is preferably connected in parallel to the first energy storage device and / or in parallel to the second energy storage device.

[0039] If a Zener diode is used, it also helps to limit the voltage and / or protect against overload.

[0040] It is therefore possible that the first energy storage device and the second energy storage device are directly connected to each other, e.g. soldered together.

[0041] The first and second energy storage devices can be arranged one above the other or next to each other.

[0042] It is therefore also possible that the solid-state accumulator consists of materials that are compatible with a co-firing process, e.g. for the production of an HTCC or LTCC multilayer component.

[0043] The solid-state electrolyte of the solid-state battery can be selected from the following compounds: Li 1+x Al x Ti 2-x (PO4)3 (0≦x≦0.6) La 0.5 Li 0.5 TiO3 Li 14 Zn(GeO4)4, Li7La3Zr2O 12 , Li 1.3 Al 0.3 Ti 1.7 (PO4)3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li 3.25 Ge 0.25 P 0.75 S4, Li3PS4 Li2S-P2S5 Li2O-V2O5-SiO2, Li3PO4 Li 3.5 Si 0.5 P0.5 O4, Li 2.9 PO 3.3 N 0.46 ,

[0044] The electrode material of the solid-state battery can be selected from the following materials: LiVOPO4 and Li3V2(PO4)3

[0045] It is possible to use the power supply circuit in an electrical component that also includes an RF transmitter, an RF receiver and / or an RF transceiver.

[0046] Appropriate antennas and front-end circuitry may also be present.

[0047] Not claimed is a method for manufacturing a hybrid power supply circuit comprising combining a capacitor with a solid-state accumulator in a compact module.

[0048] It is possible to combine a layer system for the capacitor and a layer system for the solid-state accumulator into a monolithic module using a multilayer process.

[0049] In other words, the capacitor and the solid-state accumulator are manufactured together using multilayer processing steps, resulting in a compact, monolithically integrated module.

[0050] Electrical devices with such a hybrid power supply system, or the hybrid power supply system of such a device, can be charged by various energy sources. These include photovoltaic charging systems and piezoelectric generators. Such charging systems, and others like them, differ from, for example, a charger powered by the mains electricity grid in their highly variable charging power. The hybrid power supply system is easily able to handle the associated irregular charging current without thermal or other problems.

[0051] The solid-state battery can be made of materials that are insensitive to deep discharge, possibly down to 0 V. Alternatively, an ASIC can prevent deep discharge or overcharging.

[0052] The hybrid power supply system can include additional circuit elements, such as additional passive or active circuit elements. A monitoring function can be implemented in an ASIC chip to optimize battery charging, especially during irregular charging pulses.

[0053] Important operating principles and details of preferred embodiments are explained in more detail in the schematic figures.

[0054] They show: Fig. 1: An equivalent circuit diagram of a hybrid power supply circuit. Fig. 2: A possible arrangement of the energy storage devices next to each other. Fig. 3: a possible arrangement of the energy storage devices stacked on top of each other. Fig. 4: the use of a varistor. Fig. 5: the use of an ASIC. Fig. 6: a cross-section through a corresponding component. Fig. 7: a cross-section through an alternative embodiment of the component. Fig. 8: A perspective view of a multi-layer component: Fig. 9: a possible connection with an external circuit. Fig. 10: a possible connection with a charging circuit.

[0055] Fig. Figure 1 shows an equivalent circuit diagram of a hybrid power supply circuit (HEVS) comprising a first energy storage device (ES1) and a second energy storage device (ES2). The first energy storage device (ES1) and the second energy storage device (ES2) are connected in parallel. Both energy storage devices are connected to a first terminal (A1) and a second terminal (A2). The hybrid power supply circuit can supply electrical energy to or receive electrical energy from an external circuit environment via these two terminals (A1 and A2).

[0056] The first energy storage device ES1 is a solid-state battery. The second energy storage device ES2 is preferably a capacitor.

[0057] Both the first energy storage device ES1 and the second energy storage device ES2 can preferably be configured as a multilayer component with electrode layers as structured elements in metallization layers and, in the case of the accumulator, dielectric layers or electrolyte layers arranged between them.

[0058] Fig. Figure 2 shows a possible side-by-side arrangement of the first energy storage device ES1 relative to the second energy storage device ES2. It is preferred to arrange the energy storage devices relative to each other in such a way as to achieve the smallest possible overall structure. Both the first and second energy storage devices are preferably multi-layer components with a planar structure, where the width and depth can each be significantly greater than the height.

[0059] Fig. Figure 3 shows a possible arrangement of the two energy storage devices stacked on top of each other.

[0060] Especially when the two energy storage devices are designed as planar components, it is advantageous to arrange both components on top of each other.

[0061] This allows both the first energy storage device ES1 and the second energy storage device ES2 to be manufactured as SMD-compatible individual components. They can then be stacked on top of each other, soldered together, and thus electrically connected and mechanically firmly joined.

[0062] Fig. Figure 4 shows a possible equivalent circuit diagram of a hybrid energy supply circuit (HEVS) in which a varistor V is connected in parallel to the first energy storage device ES1 and in parallel to the second energy storage device ES2. The varistor provides protection against overcharging when the energy supply circuit is charged via terminals A1 and A2.

[0063] Short voltage or charge peaks can easily be absorbed by the second energy storage device, ES2.

[0064] Fig. Figure 5 shows the use of an ASIC (application-specific integrated circuit). The ASIC is connected to the energy storage devices and the two terminals A1 and A2, and can be used to control the charging and discharging processes.

[0065] The ASIC can be embedded in an ASIC chip and designed to have the lowest possible energy consumption, i.e., to operate as energy-efficiently as possible.

[0066] Fig. Figure 6 shows a cross-section through a component in which the first energy storage device ES1 and the second energy storage device ES2 are embedded in a substrate TS. An ASIC chip is located on the top surface of the substrate. Additional circuit elements SE can be embedded in the substrate. The various components can be interconnected via metallized signal lines in or on the top surface of the substrate and via vias through the substrate.

[0067] Alternatively, it is also possible that the first and / or the second energy storage device or further circuit elements are arranged and interconnected on the top side of the carrier substrate TS.

[0068] Fig. Figure 7 shows in a cross-section the possibility of integrating the components of the first energy storage system ES1 and the components of the second energy storage system ES2 monolithically in a carrier substrate TS.

[0069] A ceramic multilayer substrate, such as an LTCC substrate or an HTCC substrate, can be used as a support substrate.

[0070] Fig. Figure 8 shows a basic structure of a multilayer component in a perspective view of a sectioned element for better visualization, which could, for example, represent the first energy storage device ES1 or the second energy storage device ES2. Metallization layers ML are arranged in a dielectric material DM. The metallization layers ML provide material for structured electrode layers. The electrode layers are arranged one above the other. Adjacent electrode layers are connected and interconnected with opposing electrodes EL1 and EL2 as outer electrodes.

[0071] Fig. Figure 9 shows the possibility of supplying external circuits or external circuit environments ES with electrical energy via the two terminals A1 and A2. A continuous load can essentially be covered by the first energy storage device ES1. Additional loads requiring high power can be supplied by the second energy storage device ES2.

[0072] Fig. Figure 10 shows the possibility of supplying the energy storage devices with electrical energy via a charging circuit LS through terminals A1 and A2. The charging circuit can include thermal, photovoltaic, or piezoelectric generators. The second energy storage device, ES2, helps to accommodate irregular charging currents.

[0073] The external circuitry can, for example, include a transceiver RXTX and an antenna ANT to communicate with an external radio environment.

[0074] The hybrid power supply circuit is not limited to the details of the embodiments shown. It can include further circuit elements such as additional energy storage devices, additional integrated circuits, additional switches, and additional connections. Reference symbol list A1, A2 first, second connection ASIC application-specific integrated circuit = application-specific integrated circuit DM dielectric material EL1, EL2 Outer electrodes of a multilayer component ES external circuit ES1 first energy storage ES2 second energy storage HEVS hybrid power supply circuit LS charging circuit ML Metallization layer SE further circuit elements TS carrier substrate V varistor

Claims

[1] Hybrid power supply circuit (HEVS), comprising - a first energy storage unit (ES1) and - a second energy storage device (ES2), where - the first (ES1) and the second (ES2) energy storage units are combined in one module and electrically connected, - the first energy storage device (ES1) is a solid-state accumulator and - the first energy storage device (ES1) and the second energy storage device (ES2) are formed from SMD-capable individual components that are directly soldered together. [2] Power supply circuit according to the preceding claim, wherein the second energy storage device (ES2) is selected from a ceramic capacitor and a multi-layer ceramic capacitor, wherein the solid-state accumulator has structured electrode layers and electrolyte layers arranged therebetween. [3] Power supply circuit according to one of the preceding claims, further comprising an ASIC chip (ASIC) for controlling or regulating a charging or discharging process. [4] Power supply circuit according to one of the preceding claims, wherein the SMD-capable individual components are arranged one above the other or next to each other and interconnected. [5] Power supply circuit according to one of the preceding claims, wherein the first energy storage device (ES1) and the second energy storage device (ES2) are electrically conductively connected and mechanically firmly connected by soldering. [6] Power supply circuit according to one of the preceding claims, further comprising a varistor (V) and / or a Zener diode for limiting a voltage to a minimum value or a maximum value. [7] Power supply circuit according to one of the preceding claims, wherein the electrolyte layers comprise a solid electrolyte selected from the following compounds: Li 1+x Al x Ti 2-x (PO4)3 (0≦x≦0.6) La 0.5 Li 0.5 TiO3, Li 14 Zn(GeO4)4, Li7La3Zr2O 12 , Li 1.3 Al 0.3 Ti 1.7 (PO4)3, Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li 3.25 Ge 0.25 P 0.75 S4, Li3PS4, Li2S-P2S5, Li2O-V2O5-SiO2, Li3PO4, Li 3.5 Si 0.5 P 0.5 O4, Li 2.9 PO 3.3 N 0.46 , wherein the material of the electrode layers of the solid-state accumulator is selected from the following materials: LiVOPO4 and Li3V2(PO4)3. [8] Use of a power supply circuit according to one of the preceding claims in an electrical component with an RF transmitter, an RF receiver and / or an RF transceiver.

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