We demonstrate that peat moss, a wild plant that covers 3% of the earth's surface, serves as an ideal precursor to create sodium ion battery (NIB) anodes with some of the most attractive electrochemical properties ever reported for carbonaceous materials. By inheriting the unique cellular structure of peat moss leaves, the resultant materials are composed of three-dimensional macroporous interconnected networks of carbon nanosheets (as thin as 60 nm). The peat moss tissue is highly cross-linked, being rich in lignin and hemicellulose, suppressing the nucleation of equilibrium graphite even at 1100 °C. Rather, the carbons form highly ordered pseudographitic arrays with substantially larger intergraphene spacing (0.388 nm) than graphite (c/2 = 0.3354 nm). XRD analysis demonstrates that this allows for significant Na intercalation to occur even below 0.2 V vs Na/Na(+). By also incorporating a mild (300 °C) air activation step, we introduce hierarchical micro- and mesoporosity that tremendously improves the high rate performance through facile electrolyte access and further reduced Na ion diffusion distances. The optimized structures (carbonization at 1100 °C + activation) result in a stable cycling capacity of 298 mAh g(-1) (after 10 cycles, 50 mA g(-1)), with ∼150 mAh g(-1) of charge accumulating between 0.1 and 0.001 V with negligible voltage hysteresis in that region, nearly 100% cycling Coulombic efficiency, and superb cycling retention and high rate capacity (255 mAh g(-1) at the 210th cycle, stable capacity of 203 mAh g(-1) at 500 mA g(-1)).

In this work we demonstrate that biomass-derived proteins serve as an ideal precursor for synthesizing carbon materials for energy applications. The unique composition and structure of the carbons resulted in very promising electrochemical energy storage performance. We obtained a reversible lithium storage capacity of 1780 mA h g À1 , which is among the highest ever reported for any carbon-based electrode. Tested as a supercapacitor, the carbons exhibited a capacitance of 390 F g À1 , with an excellent cycle life (7% loss after 10 000 cycles). Such exquisite properties may be attributed to a unique combination of a high specific surface area, partial graphitization and very high bulk nitrogen content. It is a major challenge to derive carbons possessing all three attributes. By templating the structure of mesoporous cellular foam with egg white-derived proteins, we were able to obtain hierarchically mesoporous (pores centered at $4 nm and at 20-30 nm) partially graphitized carbons with a surface area of 805.7 m 2 g À1 and a bulk N-content of 10.1 wt%. When the best performing sample was heated in Ar to eliminate most of the nitrogen, the Li storage capacity and the specific capacitance dropped to 716 mA h g À1 and 80 F g À1 , respectively. Broader contextIt has been well-known that the residue nitrogen le in the activated carbons has a positive effect of on their electrochemical properties. However, this effect is limited by the relatively low content of nitrogen. Aer carefully tuning the preparation procedure to maximize the nitrogen functionalities in carbons, researchers recently found the N-rich carbons have much more potential than we achieved before for various energy applications, including supercapacitors, Li storage and ORR. The key is to make carbons with high surface area, right pore structure and high nitrogen content. In this work, by utilizing a very common Nrich renewable biomass-egg white and a well-known MCF template, we have obtained a mesoporous N-rich carbon with 10% N, bimodal mesopores and a specic surface area of 800 m 2 g À1 . The achieved carbon shows extremely promising properties for both Li storage (1780 mA h g À1 ) and supercapacitor (390 F g À1 ). Considering the large molecular weight of the proteins in egg white, the proteins from various biomass/biowaste may also be used as precursor. Beside the environmental benets and low cost, another signicant advantage of deriving carbons from biomass is the excellent cycle life since the functionalities are rmly incorporated in the backbone of carbons.

We created unique interconnected partially graphitic carbon nanosheets (10-30 nm in thickness) with high specific surface area (up to 2287 m(2) g(-1)), significant volume fraction of mesoporosity (up to 58%), and good electrical conductivity (211-226 S m(-1)) from hemp bast fiber. The nanosheets are ideally suited for low (down to 0 °C) through high (100 °C) temperature ionic-liquid-based supercapacitor applications: At 0 °C and a current density of 10 A g(-1), the electrode maintains a remarkable capacitance of 106 F g(-1). At 20, 60, and 100 °C and an extreme current density of 100 A g(-1), there is excellent capacitance retention (72-92%) with the specific capacitances being 113, 144, and 142 F g(-1), respectively. These characteristics favorably place the materials on a Ragone chart providing among the best power-energy characteristics (on an active mass normalized basis) ever reported for an electrochemical capacitor: At a very high power density of 20 kW kg(-1) and 20, 60, and 100 °C, the energy densities are 19, 34, and 40 Wh kg(-1), respectively. Moreover the assembled supercapacitor device yields a maximum energy density of 12 Wh kg(-1), which is higher than that of commercially available supercapacitors. By taking advantage of the complex multilayered structure of a hemp bast fiber precursor, such exquisite carbons were able to be achieved by simple hydrothermal carbonization combined with activation. This novel precursor-synthesis route presents a great potential for facile large-scale production of high-performance carbons for a variety of diverse applications including energy storage.

This is the first report of a hybrid sodium ion capacitor (NIC) with the active materials in both the anode and the cathode being derived entirely from a single precursor: peanut shells, which are a green and highly economical waste globally generated at over 6 million tons per year. The electrodes push the envelope of performance, delivering among the most promising sodiation capacity -rate capability -cycling retention combinations reported in literature for each materials 4 materials being desirable. Previously, researchers have primarily focused on improving the power capability of the anode in order to catch up with the fast kinetics of the capacitive cathode. 39,42,44,46 NIC devices have been recently fabricated using the following anode-cathode combinations: V 2 O 5 /CNT//AC, 38 Na x H 2-x Ti 3 O 7 //AC 43 , with AC meaning conventional activated carbon. This creates a necessity to include excess mass (i.e. volume), generally several times more than that of the anode, in order to achieve the charge balance between the two electrodes. 39,43,44 The Na ion insertion processes into the bulk of the negative electrodes are known to be substantially more kinetically sluggish than those for Li, 4,49,50 posing a secondary major challenge to achieving attractive Na ion -based hybrid devices.An inexpensive carbon-based negative electrode with a Na redox potential near Na/Na + would not only provide a cost advantage over the inherently more costly inorganic materials but would also maximize the device energy density. 11,40,49,51,52 Ideally such electrode materials would also be truly green, 7,8,20,26,30,31,33,47,53,54,55,56,57,58,59,60,61 being derived from organic waste products that otherwise possess no economic value. Peanuts are a globally cultivated legume food staple, with the peanut shells having only limited commercial end-use as filler in animal feed or as charcoal. 62 In 2010 the peanut plant was cultivated on 21 million hectares worldwide, 63 producing approximately 20 million tons, with an estimated value of 9 billion USD. 64 This produces roughly 6 million tons of peanut shell waste.Researchers have prepared activated carbons from peanut shells and explored their 5 applications in environmental science (e.g. sorbents for organic and metal pollutants removal 65,66 ) and energy storage (e.g. supercapacitor, 67,68 lithium ion battery 69,70 ).These "classical" activated carbons were prepared by direct pyrolysis followed by high temperature activation. 62,67,71,72 In terms of the synthesis methodology and by the resultant structure and performance, such ACs are analogous to commercial products, which are micro-scale particulates with tortuous 3D pore networks. In terms of the synthesis methodology and by the resultant structure and performance, such ACs are analogous to commercial products, which are micro-scale particulates with tortuous 3D pore networks. In this work we take an alternative approach: We tailor the synthesis process to take full advantage of the unique structure of the peanut shell and actuall...

Anatase TiO2 nanocrystals were successfully employed as anodes for rechargeable Na-ion batteries for the first time. The mesoporous electrodes exhibited a highly stable reversible charge storage capacity of ~150 mA h g(-1) over 100 cycles, and were able to withstand high rate cycling, fully recovering this capacity after being cycled at rates as high as 2 A g(-1).

Supercapacitor electrode materials are synthesized by carbonizing a common livestock biowaste in the form of chicken eggshell membranes. The carbonized eggshell membrane (CESM) is a three‐dimensional macroporous carbon film composed of interwoven connected carbon fibers containing around 10 wt% oxygen and 8 wt% nitrogen. Despite a relatively low surface area of 221 m2 g−1, exceptional specific capacitances of 297 F g−1 and 284 F g−1 are achieved in basic and acidic electrolytes, respectively, in a 3‐electrode system. Furthermore, the electrodes demonstrate excellent cycling stability: only 3% capacitance fading is observed after 10 000 cycles at a current density of 4 A g−1. These very attractive electrochemical properties are discussed in the context of the unique structure and chemistry of the material.

A kind of activated carbon with further carbon dioxide and potassium hydroxide activations for hydrogen storage was investigated. The carbon dioxide and potassium hydroxide activations have apparently different effects on the pore structures and textures of the activated carbon which closely associated with the hydrogen storage properties. The potassium hydroxide activation can remarkably donate microporosity to the frameworks of the activated carbon. One of the resultant porous carbons exhibited a high surface area of up to 3190 m(2) g(-1) and large gravimetric hydrogen uptake capacity of 7.08 wt % at 77 K and 20 bar, which is one of the largest data reported for the porous carbon materials. This result suggests that the porous carbon with large amounts of active sites, high surface area, and high micropore volume related to optimum pore size could achieve high gravimetric hydrogen storage.

A highly functionalized activated carbon with a colossal pseudocapacitance of more than 500 F g−1 was derived from biomass and used to boost the energy of an asymmetric supercapacitor tremendously.