Direct pyrolysis to convert biomass to versatile 3D carbon nanotubes/mesoporous carbon architecture:conversion mechanism and electrochemical performance

The massive conversion of resourceful biomass to carbon nanomaterials not only opens a new avenue to effective and economical disposal of biomass,but provides a possibility to produce highly valued functionalized carbon-based electrodes for energy storage and conversion systems.In this work,biomass is applied to a facile and scalable one-step pyrolysis method to prepare three-dimensional(3D)carbon nanotubes/mesoporous carbon architecture,which uses transition metal inorganic salts and melamine as initial precursors.The role of each employed component is investigated,and the electrochemical performance of the attained product is explored.Each component and precise regulation of their dosage is proven to be the key to successful conversion of biomass to the desired carbon nanomaterials.Owing to the unique 3D architecture and integration of individual merits of carbon nanotubes and mesoporous carbon,the as-synthesized carbon nanotubes/mesoporous carbon hybrid exhibits versatile application toward lithium-ion batteries and Zn-air batteries.Apparently,a significant guidance on effective conversion of biomass to functionalized carbon nanomaterials can be shown by this work.

Heat-resistant Al_(2)O_(3) nanowire-polyetherimide separator for safer and faster lithium-ion batteries

Poor heat/flame-resistance of polyolefin(e.g.,polyethylene and polypropylene)separators and high flammability of organic electrolytes used in today’s lithium-ion batteries(LIBs)may trigger rare yet potentially catastrophic safety issues.Here,we mitigate this challenge by developing a heat-resistant and flame-retardant porous composite membrane composed of polyetherimide(PEI)and Al_(2)O_(3) nanowires(NWs).The membranes are fabricated based on an industrially scalable non-solvent-induced phase separation process,which results in an intimately interconnected porous network of Al_(2)O_(3) NWs and PEI.The produced composite membranes exhibit excellent flexibility,thermal stability,and flame-retardancy.Importantly,the composite membranes exhibit minimal thermal shrinkage and superior tensile strength(16 MPa)at temperatures as high as 200℃,significantly exceeding the performance of conventional polyolefin separators.Compared with commercial separators,their superior wettability and higher ionic conductivity(by up to 2.4 times)when filled with the same electrolyte,larger electrolyte uptake(-190 wt.%),as well as improved cycle and rate performance demonstrated in LiNiMnCoO_(2)(NCM)-based LIBs make them attractive choices for a variety of electrochemical energy storage devices.