Provided are new solid-state electrochemical cells and methods for fabricating these cells. In some examples, a solid-state electrochemical cell is assembled using a negative electrode, a positive electrode, and a gel-polymer electrolyte layer, which is disposed and provides ionic communications between these electrodes. Prior to this assembly, the negative electrode is free from electrolytes. The negative electrode is fabricated using a coating technique, e.g., forming a slurry, comprising a polymer binder and one or more negative active materials structures, such as silicon, graphite, and the like. The porosity, size, and other characteristics of the negative active materials structures and of the resulting coated later are specifically controlled to ensure operation with the gel-polymer electrolyte layer or, more specifically, high-rate charge and discharge, e.g., greater than 1 mA/cm.sup.2. The gel-polymer electrolyte layer releases some of its liquid electrolyte after the interface with the negative electrode is formed.

In an embodiment, the present disclosure pertains to a method of creating a supercapacitor. The method includes forming an anode and a cathode, each composed of a substrate having at least one of a lignin, a lignin-based composite, activated carbon, a plant extract, a cellulose by-product, biofuel waste, one or more metals, a metal oxide, a monometallic tungstate, or a bimetallic tungstate, and sandwiching an electrolyte coated separator between the anode and the cathode. In an addition embodiment, the present disclosure pertains to an electrode composed of a particle-decorated lignin. In some embodiments, the particle-decorated lignin includes particles that can include, without limitation, MnO.sub.2, NiWO.sub.4, MnO.sub.2, NiCoWO.sub.4, CoWO.sub.4, and combinations thereof. In a further embodiment, the present disclosure pertains to a supercapacitor made via the methods of the present disclosure.

In an embodiment, the present disclosure pertains to a method of creating a supercapacitor. The method includes forming an anode and a cathode, each composed of a substrate having at least one of a lignin, a lignin-based composite, activated carbon, a plant extract, a cellulose by-product, biofuel waste, one or more metals, a metal oxide, a monometallic tungstate, or a bimetallic tungstate, and sandwiching an electrolyte coated separator between the anode and the cathode. In an addition embodiment, the present disclosure pertains to an electrode composed of a particle-decorated lignin. In some embodiments, the particle-decorated lignin includes particles that can include, without limitation, MnO.sub.2, NiWO.sub.4, MnO.sub.2, NiCoWO.sub.4, CoWO.sub.4, and combinations thereof. In a further embodiment, the present disclosure pertains to a supercapacitor made via the methods of the present disclosure.

A bipolar capacitor assisted battery includes a bipolar capacitor including a first capacitor, and a second capacitor. The second capacitor is connected in series with the first capacitor. A lithium ion battery is connected in parallel to the bipolar capacitor.

A bipolar capacitor assisted battery includes a bipolar capacitor including a first capacitor, and a second capacitor. The second capacitor is connected in series with the first capacitor. A lithium ion battery is connected in parallel to the bipolar capacitor.

Disclosed herein is a method for using a high temperature rechargeable energy storage device comprising (a) obtaining an HTRESD; and (b) at least one of (1) cycling the HTRESD by alternatively charging and discharging the HTRESD at least twice over a duration of 20 hours and (2) maintaining a voltage across the HTRESD for 20 hours, such that the HTRESD exhibits a peak power density between 0.005 W/liter and 75 kW/liter after 20 hours when operated at an ambient temperature in an operating temperature range comprising between about −40° C. and about 210° C.

Disclosed herein is a method for using a high temperature rechargeable energy storage device comprising (a) obtaining an HTRESD; and (b) at least one of (1) cycling the HTRESD by alternatively charging and discharging the HTRESD at least twice over a duration of 20 hours and (2) maintaining a voltage across the HTRESD for 20 hours, such that the HTRESD exhibits a peak power density between 0.005 W/liter and 75 kW/liter after 20 hours when operated at an ambient temperature in an operating temperature range comprising between about −40° C. and about 210° C.

A vibration energy harvester includes: a pair of electrodes provided so as to face opposite each other, with at least one of the pair of electrodes allowed to move; and an ion gel provided between the pair of electrodes, which is formed by using an ionic liquid, wherein: as an external vibration causes the electrode to move along a direction in which a distance between the pair of electrodes changes, power is generated through a change in an area of an electric double layer formed on two sides of an interface of each electrode and the ion gel.

An embodiment is directed to an electrode composition for use in an energy storage device cell. The electrode comprises composite particles, each comprising carbon that is biomass-derived and active material. The active material exhibits partial vapor pressure below around 10.sup.−13 torr at around 400 K, and an areal capacity loading of the electrode composition ranges from around 2 mAh/cm.sup.2 to around 16 mAh/cm.sup.2.

An embodiment is directed to an electrode composition for use in an energy storage device cell. The electrode comprises composite particles, each comprising carbon that is biomass-derived and active material. The active material exhibits partial vapor pressure below around 10.sup.−13 torr at around 400 K, and an areal capacity loading of the electrode composition ranges from around 2 mAh/cm.sup.2 to around 16 mAh/cm.sup.2.