A dual pore carbon aerogel based air cathode for a highly rechargeable lithium-air battery

Abstract

International audienceCathode structure plays a vital role in lithium-air battery for that it can provide space for discharged products accommodation and free path for oxygen, e− and Li+ transport. However, pore blockage, cathode passivation and degradation all result in low discharge rates and poor cycling capability. To get rid of these predicaments, a novel highly conductive dual pore carbon aerogel based air cathode is fabricated to construct a lithium-air battery, which exhibits 18 to 525 cycles in the LiTFSI/sulfolane electrolyte at a current density varying from 1.00 mA cm−2 to 0.05 mA cm−2, accompanied by a high energy efficiency of 78.32%. We postulate that the essence lies in that the as-prepared air cathode inventively create a suitable tri-phase boundary reaction zone, facilitating oxygen and Li+ diffusion in two independant pore channels, thus realizing a relative higher discharge rate capability, lower pore blockage and cathode passivation. Further, pore structure, carbon loading, rate capability, discharge depth and the air's effect are exploited and coordinated, targeting for a high power and reversible lithium-air battery. Such nano-porous carbon aerogel air cathode of novel dual pore structure and material design is expected to be an attractive alternative for lithium-air batteries and other lithium based batteries

Highly ordered and ultra-long carbon nanotube arrays as air cathodes for high-energy-efficiency Li-oxygen batteries

“…In addition, introducing catalysts or "promoters" into the cathodes of LieO 2 batteries has been reported as a mean to reduce the battery polarization [19,26,27]. Compared with conventional solid catalysts (precious metals, transitional oxides etc.…”

Monitoring the Location of Cathode-Reactions in Li-O2Batteries

“…Several authors have reported an increase in the specific energy of these batteries with increasing carbon mesopore volume in the air electrode. [24][25][26] In this sense, several approaches can be defined to improve oxygen diffusion across the electrode: (i) reduction of the electrode thickness in order to minimize the diffusion distance, and (ii) minimization of electrode pore overflow to allow the diffusion of oxygen.…”

The Influence of Carbonaceous Matrices and Electrocatalytic MnO2 Nanopowders on Lithium-Air Battery Performances

“…All of the specific capacities are calculated by dividing the charge amount by active material weight, that is the sum of carbonaceous support and electrocatalytic nanopowders, when present. GDE-H ( Figure 5 a, Curve 2) and GDE-M ( Figure 5 a, Curve 3), exploiting HCMSC and MCC carbon matrices, respectively, behave better than either the reference cathodes or the newly-proposed material, like graphene [ 47 , 48 ]. MCC allows reaching a specific capacity of 1560 mAh·g −1 , while the HCMSC-based cathode gives 1150 mAh·g −1 .…”