以五氧化二钒干凝胶、碳酸锰、磷酸二氢铵、碳酸锂、乙炔黑为原料,采用固相法在相对较低的温度条件下合成了x Li Mn PO4·y Li3V2(PO4)3锂离子电池复合正极材料。采用X射线衍射(XRD)、扫描电镜(SEM)对其晶体结构和表面形貌进行表征...以五氧化二钒干凝胶、碳酸锰、磷酸二氢铵、碳酸锂、乙炔黑为原料,采用固相法在相对较低的温度条件下合成了x Li Mn PO4·y Li3V2(PO4)3锂离子电池复合正极材料。采用X射线衍射(XRD)、扫描电镜(SEM)对其晶体结构和表面形貌进行表征。结果表明,750℃下烧结15 h合成的3Li Mn PO4·Li3V2(PO4)3为结晶良好的两相结构,颗粒粒径较小且分布比较均匀,其在室温、0.2 C倍率下首次充放电容量分别为144.8 m Ah/g和139.8 m Ah/g,循环50次后容量为130.5 m Ah/g。展开更多
Ultra-high nickel material is considered to be a promising cathode material.However,with the increase of nickel content,the interfacial side reactions between the cathode and electrolyte become increasingly serious.He...Ultra-high nickel material is considered to be a promising cathode material.However,with the increase of nickel content,the interfacial side reactions between the cathode and electrolyte become increasingly serious.Herein,an atomically controllable ionic conductor Li_(3)PO_(4)(LPO)coating is deposited on the LiNi_(0.90)Co_(0.06)Mn_(0.04)O_(2)(NCM9064)based electrode by the atomic layer deposition method.The results shows that the LPO coating is uniformly and densely covered on the surface of secondary particles of NCM9064,helping to prevent the direct contact between the electrolyte and cathode during the chargingdischarging process.In addition,the coating layer is electrochemically stable.As a result,the interfacial side reactions during the long cycle are effectively suppressed,and the solid electrolyte interphase layer at the interface is stabilized.The electrode with 20 layers of LPO deposition(ALD-LPO-20)exhibits an excellent capacity retention of 81%after 200 cycles in 2.8-4.3 V at 25℃,which is 18%higher than the unmodified material(ALD-LPO-0).Besides,the moderate LPO coating improves the rate capability and high temperature cycling performance of NCM9064.This study provides a method for the modification of ultra-high nickel cathode materials and corresponding electrodes.展开更多
Fast charging and high-power delivering batteries are highly demanded in mobile electronics,electric vehicles and grid energy storage,but there are full of challenges.The star-material Li_(3)V_(2)(PO_(4))_(3) is demon...Fast charging and high-power delivering batteries are highly demanded in mobile electronics,electric vehicles and grid energy storage,but there are full of challenges.The star-material Li_(3)V_(2)(PO_(4))_(3) is demonstrated as a promising high-rate cathode material meeting the above requirements.Herein,we report the carbon decorated Li_(3)V_(2)(PO_(4))_(3) (LVP/C) cathode prepared via a facile method,which displays a remarkable high-rate capability and long-term cycling performance.Briefly,the prepared LVP/C delivers a high discharge capacity of 122 mAh g^(-1)(-93% of the theoretical capacity) at a high rate up to 20 C and a superior capacity retention of 87.1% after 1000 cycles.Importantly,by applying a combination of X-ray absorption spectroscopy and full-range mapping of resonant inelastic X-ray scattering,we clearly elucidate the structural and chemical evolutions of LVP upon various potentials and cycle numbers.We show unambiguous spectroscopic evidences that the evolution of the hybridization strength between V and O in LVP/C as a consequence of lithiation/delithiation is highly reversible both in the bulk and on the surface during the discharge-charge processes even over extended cycles,which should be responsible for the remarkable electrochemical performance of LVP/C.Our present study provides not only an effective synthesis strategy but also deeper insights into the surface and bulk electrochemical reaction mechanism of LVP,which should be beneficial for the further design of high-performance LVP electrode materials.展开更多
Li-rich manganese-based materials are considered to be the mainstream cathode materials for next-generation lithium-ion batteries due to high discharge capacity and low cost,but poor cycle life and high temperature pe...Li-rich manganese-based materials are considered to be the mainstream cathode materials for next-generation lithium-ion batteries due to high discharge capacity and low cost,but poor cycle life and high temperature performance limit their development.Herein,LiZr_(2)(PO_(4))_(3)(LZPO)is coated on the surface of spherical Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)(LMNCO)material by a simple wet chemical method.The LZPO layer not only has the function of traditional coating layer to inhibit the occurrence of side reactions between electrolyte and LMNCO surface but also promotes the formation of spinel phase in the layered structure,increases the content of lattice oxygen,and reduces the content of absorbed oxygen.Thus,LZPO coated LMNCO has a more stable layered structure during cycling compared pure LMNCO,which improves effectively its long life and high temperature performance.The capacity loss rate of LZPO coated LMNCO is only 16.2%and 11.9%after 350 cycles at 25℃and 200 cycles at 50℃,respectively.Moreover,the capacity retention rate of the full cell composed of LZPO coated LMNCO and graphite is 70.7%after 200 cycles at 1.0 C.The coating layer toward stable surface structure can provide an idea for the modification of cathode materials,especially for Li-rich manganese-based materials.展开更多
超高镍正极材料具有高比能、高电压和低成本等特点,在新一代锂离子电池中备受关注,但在电池的长循环过程中会出现微裂纹、机械粉化和不可逆相变,导致差的循环性能。本研究采用简便的湿化学法制备了一系列Ca_(3)(PO_(4))_(2)包覆的超高镍...超高镍正极材料具有高比能、高电压和低成本等特点,在新一代锂离子电池中备受关注,但在电池的长循环过程中会出现微裂纹、机械粉化和不可逆相变,导致差的循环性能。本研究采用简便的湿化学法制备了一系列Ca_(3)(PO_(4))_(2)包覆的超高镍LiNi_(0.91)Co_(0.06)Al_(0.03)O_(2)材料(NCA@n CP)。其中,NCA@1CP在1C (1C=200 m A/g)、2.7~4.3 V下可获得204.8 m Ah/g的放电比容量,100圈循环后容量保持率为91.5%,甚至在2C的倍率下循环300圈后仍保留153.4 mAh/g的放电比容量。表征结果证实该包覆层可抑制材料的Li/Ni混排、不可逆相变和机械粉化,从而大幅提升了循环稳定性。本研究表明Ca_(3)(PO_(4))_(2)包覆策略在提升超高镍正极材料储锂稳定性方面具有较大的应用潜力。展开更多
文摘以五氧化二钒干凝胶、碳酸锰、磷酸二氢铵、碳酸锂、乙炔黑为原料,采用固相法在相对较低的温度条件下合成了x Li Mn PO4·y Li3V2(PO4)3锂离子电池复合正极材料。采用X射线衍射(XRD)、扫描电镜(SEM)对其晶体结构和表面形貌进行表征。结果表明,750℃下烧结15 h合成的3Li Mn PO4·Li3V2(PO4)3为结晶良好的两相结构,颗粒粒径较小且分布比较均匀,其在室温、0.2 C倍率下首次充放电容量分别为144.8 m Ah/g和139.8 m Ah/g,循环50次后容量为130.5 m Ah/g。
基金supported by the National Natural Science Foundation of China(No.52174285)the Science and Technology Innovation Program of Hunan Province(No.2022RC3048)+1 种基金the Key Research and Development Program of Yunnan Province(No.202103AA080019)the Research Foundation of Education Bureau of Hunan Province(No.18B477).
文摘Ultra-high nickel material is considered to be a promising cathode material.However,with the increase of nickel content,the interfacial side reactions between the cathode and electrolyte become increasingly serious.Herein,an atomically controllable ionic conductor Li_(3)PO_(4)(LPO)coating is deposited on the LiNi_(0.90)Co_(0.06)Mn_(0.04)O_(2)(NCM9064)based electrode by the atomic layer deposition method.The results shows that the LPO coating is uniformly and densely covered on the surface of secondary particles of NCM9064,helping to prevent the direct contact between the electrolyte and cathode during the chargingdischarging process.In addition,the coating layer is electrochemically stable.As a result,the interfacial side reactions during the long cycle are effectively suppressed,and the solid electrolyte interphase layer at the interface is stabilized.The electrode with 20 layers of LPO deposition(ALD-LPO-20)exhibits an excellent capacity retention of 81%after 200 cycles in 2.8-4.3 V at 25℃,which is 18%higher than the unmodified material(ALD-LPO-0).Besides,the moderate LPO coating improves the rate capability and high temperature cycling performance of NCM9064.This study provides a method for the modification of ultra-high nickel cathode materials and corresponding electrodes.
基金supported by Collaborative Innovation Center of Suzhou Nano Science & Technologythe Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)+5 种基金the 111 roject, Joint International Research Laboratory of Carbon-Based Functional Materials and Devicesthe National Natural Science Foundation of China (11905154)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (19KJA550004)the Natural Science Foundation of Jiangsu Province (BK20190814)the National Key R&D Program of China (No. 2016YFA0202600)supported by the Director, Office of Science, Office of Basic Energy Sciences, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231。
文摘Fast charging and high-power delivering batteries are highly demanded in mobile electronics,electric vehicles and grid energy storage,but there are full of challenges.The star-material Li_(3)V_(2)(PO_(4))_(3) is demonstrated as a promising high-rate cathode material meeting the above requirements.Herein,we report the carbon decorated Li_(3)V_(2)(PO_(4))_(3) (LVP/C) cathode prepared via a facile method,which displays a remarkable high-rate capability and long-term cycling performance.Briefly,the prepared LVP/C delivers a high discharge capacity of 122 mAh g^(-1)(-93% of the theoretical capacity) at a high rate up to 20 C and a superior capacity retention of 87.1% after 1000 cycles.Importantly,by applying a combination of X-ray absorption spectroscopy and full-range mapping of resonant inelastic X-ray scattering,we clearly elucidate the structural and chemical evolutions of LVP upon various potentials and cycle numbers.We show unambiguous spectroscopic evidences that the evolution of the hybridization strength between V and O in LVP/C as a consequence of lithiation/delithiation is highly reversible both in the bulk and on the surface during the discharge-charge processes even over extended cycles,which should be responsible for the remarkable electrochemical performance of LVP/C.Our present study provides not only an effective synthesis strategy but also deeper insights into the surface and bulk electrochemical reaction mechanism of LVP,which should be beneficial for the further design of high-performance LVP electrode materials.
基金support from the Key Project of Science and Technology Research of Chongqing Education Commission of China(No.KJZDK201801103)the Venture&Innovation Support Program for Chongqing Overseas Returnees(No.cx2019128)Scientific Research Foundation of Chongqing University of Technology(No.2022ZDZ004).
文摘Li-rich manganese-based materials are considered to be the mainstream cathode materials for next-generation lithium-ion batteries due to high discharge capacity and low cost,but poor cycle life and high temperature performance limit their development.Herein,LiZr_(2)(PO_(4))_(3)(LZPO)is coated on the surface of spherical Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2)(LMNCO)material by a simple wet chemical method.The LZPO layer not only has the function of traditional coating layer to inhibit the occurrence of side reactions between electrolyte and LMNCO surface but also promotes the formation of spinel phase in the layered structure,increases the content of lattice oxygen,and reduces the content of absorbed oxygen.Thus,LZPO coated LMNCO has a more stable layered structure during cycling compared pure LMNCO,which improves effectively its long life and high temperature performance.The capacity loss rate of LZPO coated LMNCO is only 16.2%and 11.9%after 350 cycles at 25℃and 200 cycles at 50℃,respectively.Moreover,the capacity retention rate of the full cell composed of LZPO coated LMNCO and graphite is 70.7%after 200 cycles at 1.0 C.The coating layer toward stable surface structure can provide an idea for the modification of cathode materials,especially for Li-rich manganese-based materials.
文摘超高镍正极材料具有高比能、高电压和低成本等特点,在新一代锂离子电池中备受关注,但在电池的长循环过程中会出现微裂纹、机械粉化和不可逆相变,导致差的循环性能。本研究采用简便的湿化学法制备了一系列Ca_(3)(PO_(4))_(2)包覆的超高镍LiNi_(0.91)Co_(0.06)Al_(0.03)O_(2)材料(NCA@n CP)。其中,NCA@1CP在1C (1C=200 m A/g)、2.7~4.3 V下可获得204.8 m Ah/g的放电比容量,100圈循环后容量保持率为91.5%,甚至在2C的倍率下循环300圈后仍保留153.4 mAh/g的放电比容量。表征结果证实该包覆层可抑制材料的Li/Ni混排、不可逆相变和机械粉化,从而大幅提升了循环稳定性。本研究表明Ca_(3)(PO_(4))_(2)包覆策略在提升超高镍正极材料储锂稳定性方面具有较大的应用潜力。
