The past two decades have shown that the exploration of properties on the nanoscale can lead to substantially new insights regarding fundamental issues, but also to novel technological perspectives. Simultaneously it became so fashionable to decorate activities with the prefix 'nano' that it has become devalued through overuse. Regardless of fashion and prejudice, this article shows that the crystallizing field of 'nanoionics' bears the conceptual and technological potential that justifies comparison with the well-acknowledged area of nanoelectronics. Demonstrating this potential implies both emphasizing the indispensability of electrochemical devices that rely on ion transport and complement the world of electronics, and working out the drastic impact of interfaces and size effects on mass transfer, transport and storage. The benefits for technology are expected to lie essentially in the field of room-temperature devices, and in particular in artificial self-sustaining structures to which both nanoelectronics and nanoionics might contribute synergistically.

This critical review presents the state of the art research progress, proposes strategies to improve the conductivity of solid electrolytes, discusses the chemical and electrochemical stabilities, and uncovers future perspectives for solid state batteries.

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Heteroatom (N or S)-doped graphene with high surface area is successfully synthesized via thermal reaction between graphene oxide and guest gases (NH 3 or H 2 S) on the basis of ultrathin graphene oxide-porous silica sheets at high temperatures. It is found that both N and S-doping can occur at annealing temperatures from 500 to 1000 ° C to form the different binding confi gurations at the edges or on the planes of the graphene, such as pyridinic-N, pyrrolic-N, and graphitic-N for N-doped graphene, thiophenelike S, and oxidized S for S-doped graphene. Moreover, the resulting N and S-doped graphene sheets exhibit good electrocatalytic activity, long durability, and high selectivity when they are employed as metal-free catalysts for oxygen reduction reactions. This approach may provide an effi cient platform for the synthesis of a series of heteroatom-doped graphenes for different applications.

Hybrid organic-inorganic lead halide perovskite APbX3 pigments, such as methylammonium lead iodide, have recently emerged as excellent light harvesters in solid-state mesoscopic solar cells. An important target for the further improvement of the performance of perovskite-based photovoltaics is to extend their optical-absorption onset further into the red to enhance solar-light harvesting. Herein, we show that this goal can be reached by using a mixture of formamidinium (HN=CHNH3 (+), FA) and methylammonium (CH3 NH3 (+), MA) cations in the A position of the APbI3 perovskite structure. This combination leads to an enhanced short-circuit current and thus superior devices to those based on only CH3 NH3 (+). This concept has not been applied previously in perovskite-based solar cells. It shows great potential as a versatile tool to tune the structural, electrical, and optoelectronic properties of the light-harvesting materials.