Gabriel E. Pérez

ISIS Neutron and Muon Source · Crystallography Group

Neutron and muon characterisation techniques offer unique capabilities for investigating the complex structure and dynamics of rechargeable battery systems. Whilst the non-monotonic interaction of the neutron with the nuclei of...

In a proof‐of‐concept study, this work demonstrates that incorporating a specifically designed block copolymer as an interfacial layer between a charge transport layer and the photoactive layer in organic solar cells can enhance the interface between these layers leading to both performance and stability improvements of the device. This is achieved...

Doping poly(3,4-ethylenedioxythiophene):poly(styrene sulfonate) (PEDOT:PSS) is known to improve its conductivity; however, little is known about the thin-film structure of PEDOT:PSS when doped with an asymmetrically charged dopant. In this study, PEDOT:PSS was doped with different concentrations of the zwitterion 3-(N,N dimethylmyristylammonio)prop...

The interchain spacing and screening length modification of deuterated PSS (d-PSS) backbone chains in zwitterion-doped PEDOT:d-PSS were studied as a function of the doping concentration using small angle neutron scattering. Results suggest that the dopant, 3-(N,N-Dimethylmyristylammonio)propanesulfonate (DYMAP), forms worm-like micelle structures i...

The crystallization of poly(3-hexylthiophene) (P3HT) to form nanowires has attracted considerable interest because this process significantly increases the hole mobility when compared to amorphous P3HT, leading to improved performance in photovoltaic and other organic electronic devices. However, full characterization of the crystallization self-as...

In layered lithium transition metal oxide cathodes, high voltage operation is accompanied by the formation of oxygen dimers, which are widely used as an indicator of oxygen-redox activity. However, understanding the role that oxygen dimerisation plays in facilitating charge compensation is still needed. Here, Li2NiO3 (a 3d8L2-containing compound, w...

Understanding charge compensation in Li-ion battery cathodes is crucial for improving specific capacity and cycle life. This study clarifies some of the ambiguities and inaccuracies of the commonly used ionic-bonding model that requires separate transition metal (TM) and oxygen redox regimes, using an archetypal layered oxide cathode, LiNi0.8Mn0.1C...

Sodium-ion battery technology is a promising and more sustainable alternative to its more conventional lithium-ion based counterpart. The most common anode material for these systems is a disordered form of...

Ni-rich layered oxide cathode materials such as LiNi0.8Mn0.1Co0.1O2 (NMC811) are widely tipped as the next-generation cathodes for lithium-ion batteries. The NMC class offers high capacities but suffers an irreversible first cycle capacity loss, a result of slow Li+ diffusion kinetics at a low state of charge. Understanding the origin of these kine...

Short-range ordering in cation-disordered cathodes can have a significant effect on their electrochemical properties. Here, we characterise the cation short-range order in the antiperovskite cathode material Li2FeSO, using density functional theory, Monte Carlo simulations, and synchrotron X-ray pair-distribution-function data. We predict partial s...

Doping or alloying of the cations on the A-site and halides on the X site of ABX3 perovskites has been demonstrated as a successful technique for improving moisture stability of perovskite films for optoelectronic applications. Despite structural and electrical stability improvements, these films still undergo moisture induced degradation to Lead I...

A need for lithium-ion cathodes that have a reduced dependence on scarce elements, such as cobalt, has been prompted by surge in eco-consciousness over the past decade. The spinel-type LiNi 0.5 Mn 1.5 O 4 (LNMO) cathodes, with high operating voltages (ca. 4.7V vs Li ⁺ /Li) and energy densities (ca. 650 Wh kg ⁻¹ ), have received particular attention...

The impact of several solvent processing additives (1-chloronaphthalene, methylnaphthalene, hexadecane, 1-phenyloctane, and p-anisaldehyde), 3% v/v in o-dichlorobenzene, on the performance and morphology of poly[(5,6-difluoro-2,1,3-benzothiadiazol-4,7-diyl)-alt-(3,3‴-di(2-octyldodecyl)-2,2′,5′,22033,5″,2‴-quaterthiophen-5,5‴-diyl)] (PffBT4T-2OD):[6...

Transitioning to electrified transport requires improvements in sustainability, energy density, power density, lifetime, and approved the cost of lithium-ion batteries, with significant opportunities remaining in the development of next-generation cathodes. This presents a highly complex, multiparameter optimization challenge, where developments in...

The impact of the additive 1,8-diiodooctane on the morphology of bulk-heterojunction solar cells based on the systems P3HT:PC71BM, PTB7:PC71BM and PTB7-Th:PC71BM is studied using a combination of Small Angle Neutron Scattering (SANS) and Atomic Force Microscopy (AFM). The results clearly show that while in the P3HT:PC71BM system, the additive DIO p...

An anionic conjugated polyelectrolyte poly[(9,9-bis(4-sulfonatobutyl sodium) fluorene-alt-phenylene)- ran-(4,7-di-2-thienyl-2,1,3-benzothiadiazole-alt-phenylene)] which exhibits good solubility in water was synthesised via Suzuki-cross coupling. This conjugated polyelectrolyte was used as an additive in the hole transporting layer within organic ph...