qas: question: What's the cathode?
answers: answer_id: 77060
question_id: 66158
text:  nanomesh-based
context: One should note that in this first demonstration of the nanomesh-based cathodes, the thickness of the electrodes of few micrometres remains insufficient for practical application in Li-ion batteries that require thicker electrodes, in the range of tens of micrometres. Thus, the next natural step is the realization of thicker electrodes, which should be feasible given the up-scalable character of their electro-fabrication. Also, the cracks observed in the electrodes after thermal activation of LMO could somewhat affect the performance and integration of the electrodes in batteries. Such cracking originates from the expanding volume of the drop-cast LiOH during its solidification, the thermomechanical stress exerted on the nanowires during the relatively rapid ramp-up phase of annealing or the capillary forces acting on the nanomesh structure during the final drying. Further studies could address this by changing the lithium precursor to a gaseous one, pre-annealing of the nanowires to relieve the internal stress, lowering the heating rate during the conversion or optimization of drying (e.g. through supercritical drying). Furthermore, the highly nanostructured character of our cathodes comes at an expense of a lower thermal budget during the integration of the current collector with the active material, a sloping potential during the discharge and an increased rate of side-reactions. Although compared to other 3D cathodes the nanomesh cathode shows a similar cycling stability (78% of initial capacity after 50 cycles at 1.2C), it will need to be further increased for practical device applications. A detailed post-mortem analysis of the electrodes could be helpful in choosing an appropriate route for mitigating capacity fading. The potential methods include the application of thin protective coatings (such as TiO2) or integration of the electrode with a solid electrolyte (which is, anyway, inherent for application in microbatteries). A candidate electrolyte could be one of the highly-conductive solid composite electrolytes which are obtained through controlled hydrolysis of lithiated silicon alkoxides from the liquid phase and, thus, could well penetrate and impregnate the porous nanowire electrode. Also, the active electrode material could be changed to a compound with a higher cycling stability than LixMnO2, provided it can be synthesized at sufficiently low temperatures to avoid oxidation of the current collector. This could be done by, for example, electrodeposition from eutectic melts reported by Zhang et al., which was demonstrated to produce dense, high quality LiCoO2 and highly stable LiMn2O4 3D coatings at low temperatures of 260–300 °C. Contrary to the alternative low temperature sol–gel or solvothermal syntheses, molten-salt electrolysis avoids the excessive gas evolution and pressure build-up which can be detrimental to the nanoporous electrodes. Perhaps, such electrodeposition could also be extended in the future to other attractive cathode materials, allowing integration of the nanomesh with e.g. high voltage lithium nickel manganese cobalt oxides (NMC).