Hybrid electrochemical cells and modules include an anode two-sided current collector a coated with host material in anode region(s) and a cathode two-sided current collector coated with active material in cathode region(s), and one or more of the anode current collector and the cathode current collector is coated with capacitor material in one or more distinct, non-overlapping capacitor regions. A hybrid anode and/or cathode can include gaps between capacitor regions and anode regions and cathode regions. The capacitor material applied to an electrode is different from the host or active material thereof. Active material includes lithium metal oxides and lithium metal phosphates such as LiFePO.sub.4, Li(Ni.sub.xMn.sub.yCo.sub.z)O.sub.2, and/or LiMn.sub.2O.sub.4; host material includes graphite, silicon, silicon-Li/Sn/Cu alloys, Si/Co/Fe/TiSn oxides, and low-surface area carbon; and capacitor material includes activated carbon, metal oxides, and metal sulfides.

A system for discharging or charging a capacitor of a hybrid vehicle according to the present disclosure includes a target state of charge (SOC) module and a capacitor charge/discharge module. The target SOC module determines a target state of charge of the capacitor based on a speed of the vehicle. The capacitor charge/discharge module determines whether a state of charge of a capacitor is greater than a target state of charge. The capacitor charge/discharge module dissipates power from the capacitor to at least one of a battery of the vehicle and an electrical load of the vehicle when the state of charge of the capacitor is greater than the target state of charge.

A system for discharging or charging a capacitor of a hybrid vehicle according to the present disclosure includes a target state of charge (SOC) module and a capacitor charge/discharge module. The target SOC module determines a target state of charge of the capacitor based on a speed of the vehicle. The capacitor charge/discharge module determines whether a state of charge of a capacitor is greater than a target state of charge. The capacitor charge/discharge module dissipates power from the capacitor to at least one of a battery of the vehicle and an electrical load of the vehicle when the state of charge of the capacitor is greater than the target state of charge.

Provided herein are devices comprising one or more cells, and methods for fabrication thereof. The devices may be electrochemical devices. The devices may include three-dimensional supercapacitors. The devices may be microdevices such as, for example, microsupercapacitors. In some embodiments, the devices are three-dimensional hybrid microsupercapacitors. The devices may be configured for high voltage applications. In some embodiments, the devices are high voltage microsupercapacitors. In certain embodiments, the devices are high voltage asymmetric microsupercapacitors. In some embodiments, the devices are integrated microsupercapacitors for high voltage applications.

Provided herein are devices comprising one or more cells, and methods for fabrication thereof. The devices may be electrochemical devices. The devices may include three-dimensional supercapacitors. The devices may be microdevices such as, for example, microsupercapacitors. In some embodiments, the devices are three-dimensional hybrid microsupercapacitors. The devices may be configured for high voltage applications. In some embodiments, the devices are high voltage microsupercapacitors. In certain embodiments, the devices are high voltage asymmetric microsupercapacitors. In some embodiments, the devices are integrated microsupercapacitors for high voltage applications.

A system for discharging or charging a capacitor of a hybrid vehicle according to the present disclosure includes a target state of charge (SOC) module and a capacitor charge/discharge module. The target SOC module determines a target state of charge of the capacitor based on a speed of the vehicle. The capacitor charge/discharge module determines whether a state of charge of a capacitor is greater than a target state of charge. The capacitor charge/discharge module dissipates power from the capacitor to at least one of a battery of the vehicle and an electrical load of the vehicle when the state of charge of the capacitor is greater than the target state of charge.

A system for discharging or charging a capacitor of a hybrid vehicle according to the present disclosure includes a target state of charge (SOC) module and a capacitor charge/discharge module. The target SOC module determines a target state of charge of the capacitor based on a speed of the vehicle. The capacitor charge/discharge module determines whether a state of charge of a capacitor is greater than a target state of charge. The capacitor charge/discharge module dissipates power from the capacitor to at least one of a battery of the vehicle and an electrical load of the vehicle when the state of charge of the capacitor is greater than the target state of charge.

Disclosed is a hybrid electrochemical cell with a first conductor having at least one portion that is both a first capacitor electrode and a first battery electrode. The hybrid electrochemical cell further includes a second conductor having at least one portion that is a second capacitor electrode and at least one other portion that is a second battery electrode. An electrolyte is in contact with both the first conductor and the second conductor. In some embodiments, the hybrid electrochemical cell further includes a separator between the first conductor and the second conductor to prevent physical contact between the first conductor and the second conductor, while facilitating ion transport between the first conductor and the second conductor.

In an aspect, an electrode for an electrochemical cell comprises: a structure having a nano- or micro-architected three-dimensional geometry; said structure comprising one or more active carbon allotrope materials; wherein said structure is characterized by an average density less than or equal to 2.3 g cm.sup.3 and an average specific strength (strength-to-density ratio) greater than or equal to 0.004 GPa g.sup.1 cm.sup.3. Also disclosed herein are methods for making an electrode for an electrochemical cell, and methods for making an electrochemical cell.

An energy storage device can have a first graphite film, a second graphite film and an electrode divider ring between the first graphite film and the second graphite film, forming a sealed enclosure. The energy storage device may be compatible with an aqueous electrolyte or a non-aqueous electrolyte. A method of forming an energy storage device can include providing an electrode divider ring, a first graphite film and a second graphite film. The method can include pressing a first edge of the electrode divider ring into a surface of the first graphite film, and pressing a second opposing edge of the electrode divider ring into a surface of the second graphite film to form a sealed enclosure. The sealed enclosure may have as opposing surfaces the surface of the first graphite film and the surface of the second graphite film.