The rapid insertion and extraction of Li ions from a cathode material is imperative for the functioning of a Li-ion battery. In many cathode materials such as LiCoO2, lithiation proceeds through solid-solution formation, whereas in other materials such as LiFePO4 lithiation/delithiation is accompanied by a phase transition between Li-rich and Li-poor phases. We demonstrate using scanning transm...

Electron microscopy has been used to study the degradation of organic solar cells when exposed to humid air. Devices with various different combinations of commonly used organic solar cell hole transport layers and cathode materials have been investigated. In this way the ingress of water and the effect it has on devices could be studied. It was found that calcium and aluminum in the cathode bo...

Lithium-ion secondary batteries (LIBs) store electric energy via Li+ deintercalation from cathode materials. The Li+ deintercalation frequently drives a first-order phase transition of the cathode material as a result of the Li-ordering or Li-concentration effect and causes a phase separation (PS) into the Li-rich and Li-poor phases. Here, we performed an in situ microscopic investigation of th...

Lithium-iron-orthosilicate is one of the most promising cathode materials for Li-ion batteries due to its safety, environmental brightness and potentially low cost. In order to produce a low cost cathode material, Li2FeSiO4/C samples are synthesized via sol-gel (SG; one sample) and solid state (SS; two samples with different carbon content), starting from Fe (III) in the raw materials (lo...

This research aim to optimize two kinds of cathode material, LNCA and lithium manganese rich materials (LNMC), which are potential cathodes of EV since their high theoretical specific capacity. However several drawbacks need to be improved such as their low cycling performance, unstable structure, and fast voltage fading. In this project doping other ions (Na, K, Al, Sn) replacing Ni and Mn ion...

We report a trap-assisted photomultiplication (PM) phenomenon in solution-processed polymer photodetectors (PPDs) based on P3HT:PC71BM as the active layer, the maximum EQE of 16,700% is obtained for the PPDs with PC71BM doping weight ratio of 1%. The PM phenomenon is attributed to the enhanced hole tunneling injection assisted by trapped electrons in PC71BM near Al cathode, which can be demonst...

Improving cathode materials is mandatory for next-generation Li-ion batteries. Exploring polyanion compounds with high theoretical capacity such as the lithium metal orthosilicates, Li2MSiO4 is of great importance. In particular, mixed silicates represent an advancement with practical applications. Here we present results on a rapid solid state synthesis of mixed Li2(FeMnCo)SiO4 samples in a wi...

DOI: 10.1002/aenm.201600154 due to their limited specific capacity.[18,19] Very recently, we have proposed that conversion reaction materials can be attractive high capacity prelithiation materials for cathodes and demonstrated using Li2O/metal and LiF/metal nanocomposites.[20,21] For example, a high “donor” lithium-ion specific capacity of 609 mAh g−1 has been achieved for a stable nanoscaled ...

A multi-nuclear solid-state NMR approach is employed to investigate the lithium-air battery, to monitor the evolution of the electrochemical products formed during cycling, and to gain insight into processes affecting capacity fading. While lithium peroxide is identified by 17O solid state NMR (ssNMR) as the predominant product in the first discharge in 1,2-dimethoxyethane (DME) based electroly...

Much effort has been devoted to the synthesis of novel nanostructured MnO2 materials because of their unique properties and potential applications as cathode catalyst in Microbial fuel cell. Hybrid MnO2 nanostructures were fabricated by a simple hydrothermal method in this study. Their crystal structures, morphology, and electrochemical characters were carried out by FESEM, N2-adsorption-desorp...