Nickel-rich cathode materials have attracted considerable interest because of their high specific capacities,voltage ranges,and low cost.However,serious capacity attenuation and poor rate performance limit their appli...Nickel-rich cathode materials have attracted considerable interest because of their high specific capacities,voltage ranges,and low cost.However,serious capacity attenuation and poor rate performance limit their application.This study proposes a novel strategy to improve the cycle stability of the nickel-rich LiNi0.sCo0.1Mn0.1O2(NCM811)layer material by designing core-shell LiNio.sCoo.1 Mno.102(CS-NCM811).CS-NCM811 is designed by the characteristic reaction between dimethylglyoxime(C4H8N2O2)and nickel ion to form Ni(C4H7N2O2)2-The CS-NCM811 is characterized with high nickel content in its core and high manganese content on its surface,leading to a high capacity and excellent cycle stability.The capacity retention of CS-NCM811 was 72.8%,much higher than that of NCM811(47.1%)after 500 cycles at a rate of 5 C.Not only is this method a no vel strategy to desig n high capacity cathode materials but also provides some new in sights into the cycle stability of nickel-rich layered cathode materials.展开更多
K-ion batteries(KIBs)hold great promise for large-scale energy storage.However,the absence of suitable cathode materials limits their practical application.Meanwhile,rationally designing advanced cathode materials for...K-ion batteries(KIBs)hold great promise for large-scale energy storage.However,the absence of suitable cathode materials limits their practical application.Meanwhile,rationally designing advanced cathode materials for KIBs remains an open question.In this work,based on density functional theory calculations,we find that the bond stability of Fe–O is higher than that of Co–O in layered transitional metal(TM)oxides.Additionally,the K-ion migration in the Fe-based layered TM oxide has a significantly lower activation energy barrier than that in the Co-based one.Based on this theoretical prediction,we successfully synthesized a low-cost K_(0.45)Ni_(0.1)Fe_(0.1)Mn_(0.8)O_(2)cathode,which shows excellent structural stability and superior K-storage properties,including durable cycle life and high-rate capability.Moreover,the designed K_(0.45)Ni_(0.1)Fe_(0.1)Mn_(0.8)O_(2)cathode possesses a great full-cell performance with a discharge capacity of~75 mA h g^(-1) and capacity retention of~80%after 100 cycles.The results show that Fe has better structural stability and K-ion diffusion than high-cost Co in layered oxide cathodes,and this finding provides new insights into the design of low-cost and high-performance KIB layered cathodes.This work highlights the feasibility of a theory-guided experiment in screening promising battery materials.展开更多
文摘Nickel-rich cathode materials have attracted considerable interest because of their high specific capacities,voltage ranges,and low cost.However,serious capacity attenuation and poor rate performance limit their application.This study proposes a novel strategy to improve the cycle stability of the nickel-rich LiNi0.sCo0.1Mn0.1O2(NCM811)layer material by designing core-shell LiNio.sCoo.1 Mno.102(CS-NCM811).CS-NCM811 is designed by the characteristic reaction between dimethylglyoxime(C4H8N2O2)and nickel ion to form Ni(C4H7N2O2)2-The CS-NCM811 is characterized with high nickel content in its core and high manganese content on its surface,leading to a high capacity and excellent cycle stability.The capacity retention of CS-NCM811 was 72.8%,much higher than that of NCM811(47.1%)after 500 cycles at a rate of 5 C.Not only is this method a no vel strategy to desig n high capacity cathode materials but also provides some new in sights into the cycle stability of nickel-rich layered cathode materials.
基金supported by the Fundamental Research Funds for the Central Universities and the Scientific Instrument Developing Project of the Chinese Academy of Sciences(ZDKYYQ20170001)。
文摘K-ion batteries(KIBs)hold great promise for large-scale energy storage.However,the absence of suitable cathode materials limits their practical application.Meanwhile,rationally designing advanced cathode materials for KIBs remains an open question.In this work,based on density functional theory calculations,we find that the bond stability of Fe–O is higher than that of Co–O in layered transitional metal(TM)oxides.Additionally,the K-ion migration in the Fe-based layered TM oxide has a significantly lower activation energy barrier than that in the Co-based one.Based on this theoretical prediction,we successfully synthesized a low-cost K_(0.45)Ni_(0.1)Fe_(0.1)Mn_(0.8)O_(2)cathode,which shows excellent structural stability and superior K-storage properties,including durable cycle life and high-rate capability.Moreover,the designed K_(0.45)Ni_(0.1)Fe_(0.1)Mn_(0.8)O_(2)cathode possesses a great full-cell performance with a discharge capacity of~75 mA h g^(-1) and capacity retention of~80%after 100 cycles.The results show that Fe has better structural stability and K-ion diffusion than high-cost Co in layered oxide cathodes,and this finding provides new insights into the design of low-cost and high-performance KIB layered cathodes.This work highlights the feasibility of a theory-guided experiment in screening promising battery materials.
