Amorphous and Crystalline Vanadium Orthophosphate and Oxidized Multiwalled Carbon Nanotube Composites as Anode Materials in Sodium‐Ion Batteries

Abstract

Vanadium orthophosphate and oxidized multiwalled carbon nanotube (ox‐MWCNT) composites were applied as anodic electroactive materials in a sodium‐ion battery. Carbon nanotubes reduce the resistance of anodic materials, prevent drastic volume expansion, and allow easy transport of electrolyte ions, leading to an improvement in the electrochemical performance of electroactive materials. Theoretical modeling of the VPO4 /ox‐CNT interphase indicates the conducting properties of the crystalline c‐VPO4 /ox‐MWCNT composite and the significant contribution of CNTs in the charge transfer process. As anodes in sodium‐ion batteries, crystalline VPO4 (c‐VPO4 ) and amorphous VPO4 (a‐VPO4 ) exhibited initial discharge capacities of 125 mAh g−1 and 110 mAh g−1, respectively. The incorporation of vanadium phosphate into the network of ox‐MWCNTs results in a large increase in the capacity performance of electroactive materials. Discharge capacities of 1642 mAh g−1 and 1680 mAh g−1 were obtained for the first cycle in the case of the c‐VPO4 /ox‐MWCNT 50 % w/w and a‐VPO4/ox‐MWCNT 50 % w/w anodes, respectively. The capacity of these composite materials significantly decreases in the second cycle, reaching a stable capacity performance. The limiting capacity was 328 mAh g−1 for composites containing 50 % w/w ox‐MWCNTs.

Preparation of green high‐performance biomass‐derived hard carbon materials from bamboo powder waste

“…[29][30][31] In particular, the hard carbon derived from various biomass precursors, including peat moss, banana peels, corn cob, silk, wood cellulose, leaf and peanut shell, has gained significant attention and is currently under extensive research. [32][33][34][35][36][37][38][39][40][41] However, the high cost of hard carbon materials, resulting in initial Coulombic efficiencies below 75 % and capacities below 300 mA • g À 1 due to the formation of the solid electrolyte interface (SEI) layer, remains a major obstacle to their industrialization. [38] This study reports the preparation of hard carbon materials from bamboo powder waste via a high-temperature pyrolysis route and its use as anodes for SIBs.The electrochemical performance of the hard carbon derived from bamboo powder was found to be dependent on the carbonization temperature.…”

“…Research has shown that hard carbon materials are the most promising candidates for anode materials in sodium‐ion battery applications due to their larger interlayer distance, high capacity, excellent cycling stability, and lower operating potential [29–31] . In particular, the hard carbon derived from various biomass precursors, including peat moss, banana peels, corn cob, silk, wood cellulose, leaf and peanut shell, has gained significant attention and is currently under extensive research [32–41] . However, the high cost of hard carbon materials, resulting in initial Coulombic efficiencies below 75 % and capacities below 300 mA ⋅ g −1 due to the formation of the solid electrolyte interface (SEI) layer, remains a major obstacle to their industrialization [38] …”

“…[ 29 , 30 , 31 ] In particular, the hard carbon derived from various biomass precursors, including peat moss, banana peels, corn cob, silk, wood cellulose, leaf and peanut shell, has gained significant attention and is currently under extensive research. [ 32 , 33 , 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 ] However, the high cost of hard carbon materials, resulting in initial Coulombic efficiencies below 75 % and capacities below 300 mA ⋅ g −1 due to the formation of the solid electrolyte interface (SEI) layer, remains a major obstacle to their industrialization. [38] …”

SnS−SnO2Heterostructures Anchored on GO as a High‐Performance Anode for Sodium Ion Battery

“…Moreover, considering the rapid capacity decay of anode materials, it is an effective method to control the powder size at nanometer level and combine it with conductive carbon materials [16] . The promising candidates for electrode materials are those carbonaceous materials such as graphene oxide (GO) [7a] .…”

“…Moreover, considering the rapid capacity decay of anode materials, it is an effective method to control the powder size at nanometer level and combine it with conductive carbon materials. [16] The promising candidates for electrode materials are those carbonaceous materials such as graphene oxide (GO). [7a] The GO surface is rich in functional groups and defects, [17] which can provide numerous redox sites to promote the sodium reaction of SnSÀ SnO 2 , and correspondingly enhance the reaction kinetics of anode materials.…”