Nickel-rich layered oxide LiNi_(x)Co_(y)MnzO_(2)(NCM,x+y+z=1)is the most promising cathode material for high-energy lithium-ion batteries.However,conventional synthesis methods are limited by the slow heating rate,slu...Nickel-rich layered oxide LiNi_(x)Co_(y)MnzO_(2)(NCM,x+y+z=1)is the most promising cathode material for high-energy lithium-ion batteries.However,conventional synthesis methods are limited by the slow heating rate,sluggish reaction dynamics,high energy consumption,and long reaction time.To overcome these chal-lenges,we first employed a high-temperature shock(HTS)strategy for fast synthesis of the NCM,and the approaching ultimate reaction rate of solid phase transition is deeply investigated for the first time.In the HTS process,ultrafast average reaction rate of phase transition from Ni_(0.6)Co_(0.2)Mn_(0.2)(OH)_(2) to Li-containing oxides is 66.7(%s^(-1)),that is,taking only 1.5 s.An ultrahigh heating rate leads to fast reaction kinetics,which induces the rapid phase transition of NCM cathodes.The HTS-synthesized nickel-rich layered oxides perform good cycling performances(94%for NCM523,94%for NCM622,and 80%for NCM811 after 200 cycles at 4.3 V).These findings might also assist to pave the way for preparing effectively Ni-rich layered oxides for lithium-ion batteries.展开更多
Graphite is a dominant anode material for lithium-ion batteries(LIBs)due to its outstanding electrochemical performance.However,slow lithium ion(Li+)kinetics of graphite anode restricts its further application.Herein,...Graphite is a dominant anode material for lithium-ion batteries(LIBs)due to its outstanding electrochemical performance.However,slow lithium ion(Li+)kinetics of graphite anode restricts its further application.Herein,we report that high-temperature shock(HTS)can drive spent graphite(SG)into defect-rich recycled graphite(DRG)which is ideal for high-rate anode.The DRG exhibits the charging specific capacity of 323 mAh/g at a high current density of 2 C,which outperforms commercial graphite(CG,120 mAh/g).The eminent electrochemical performance of DRG can be attributed to the recovery of layered structure and partial remaining defects of SG during ultrafast heating and cooling process,which can effectively reduce total strain energy,accelerate the phase transition in thermodynamics and improve the Li+diffusion.This study provides a facile strategy to guide the re-graphitization of SG and design high performance battery electrode materials by defect engineering from the atomic level.展开更多
基金the financial support from the National Natural Science Foundation of China(Grant Nos.92372107 and 52171219).
文摘Nickel-rich layered oxide LiNi_(x)Co_(y)MnzO_(2)(NCM,x+y+z=1)is the most promising cathode material for high-energy lithium-ion batteries.However,conventional synthesis methods are limited by the slow heating rate,sluggish reaction dynamics,high energy consumption,and long reaction time.To overcome these chal-lenges,we first employed a high-temperature shock(HTS)strategy for fast synthesis of the NCM,and the approaching ultimate reaction rate of solid phase transition is deeply investigated for the first time.In the HTS process,ultrafast average reaction rate of phase transition from Ni_(0.6)Co_(0.2)Mn_(0.2)(OH)_(2) to Li-containing oxides is 66.7(%s^(-1)),that is,taking only 1.5 s.An ultrahigh heating rate leads to fast reaction kinetics,which induces the rapid phase transition of NCM cathodes.The HTS-synthesized nickel-rich layered oxides perform good cycling performances(94%for NCM523,94%for NCM622,and 80%for NCM811 after 200 cycles at 4.3 V).These findings might also assist to pave the way for preparing effectively Ni-rich layered oxides for lithium-ion batteries.
基金the financial support from the National Natural Science Foundation of China(Nos.52171219 and 91963113).
文摘Graphite is a dominant anode material for lithium-ion batteries(LIBs)due to its outstanding electrochemical performance.However,slow lithium ion(Li+)kinetics of graphite anode restricts its further application.Herein,we report that high-temperature shock(HTS)can drive spent graphite(SG)into defect-rich recycled graphite(DRG)which is ideal for high-rate anode.The DRG exhibits the charging specific capacity of 323 mAh/g at a high current density of 2 C,which outperforms commercial graphite(CG,120 mAh/g).The eminent electrochemical performance of DRG can be attributed to the recovery of layered structure and partial remaining defects of SG during ultrafast heating and cooling process,which can effectively reduce total strain energy,accelerate the phase transition in thermodynamics and improve the Li+diffusion.This study provides a facile strategy to guide the re-graphitization of SG and design high performance battery electrode materials by defect engineering from the atomic level.
