The single-crystalline Ni-rich cathodes are believed to help improve the safety of Li-ion batteries(LIBs),however,the ion-diffusion limits their high-rate performance owing to large single-crystal particles.Herein,a d...The single-crystalline Ni-rich cathodes are believed to help improve the safety of Li-ion batteries(LIBs),however,the ion-diffusion limits their high-rate performance owing to large single-crystal particles.Herein,a dual-modification strategy of surface Li_(2)TiO_(3)-coating and bulk Ti-doping has been performed to achieve high-rate single crystal LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(NCM)cathode.The Li-ion conductive Li_(2)TiO_(3) coating layer facilitates the Li-ion transfer and prevents the electrolyte erosion.Meanwhile,the robust Ti-O bonds stabilize the cubic close-packed oxygen framework and mitigate the Li/Ni disorder.The synergy endows the dual-modified NCM with enhanced de-/lithiation reaction kinetics and stable surface chemistry.A high specific capacity of 128 mAh g^(-1) is delivered even at 10 C with an extended cycle life.This finding is reckoned to pave the way for developing high energy density LIBs for long-range electric vehicles.展开更多
文摘以羟丙基淀粉为原料,对其进行乙酰化处理,制备乙酰化羟丙基复合改性淀粉.研究了乙酰化及羟丙基化反应程度控制、反应温度、反应时间、pH和淀粉乳体积分数对复合改性淀粉取代度的影响.采用中心组合实验设计确立了乙酰化羟丙基淀粉制备的数学模型,通过响应面法优化及预测乙酰化羟丙基淀粉的制备条件.结果表明,最佳工艺条件为羟丙基淀粉的取代度为0.15,淀粉乳体积分数40%,醋酸酐添加量6.65%,pH值为8.30,反应温度25℃,反应时间30 min.
基金supported by the National Natural Science Foundation of China(Nos.21838003,21978088,and 91834301)the Innovation Program of Shanghai Municipal Education Commissionthe Fundamental Research Funds for the Central Universities(No.222201718002)。
文摘The single-crystalline Ni-rich cathodes are believed to help improve the safety of Li-ion batteries(LIBs),however,the ion-diffusion limits their high-rate performance owing to large single-crystal particles.Herein,a dual-modification strategy of surface Li_(2)TiO_(3)-coating and bulk Ti-doping has been performed to achieve high-rate single crystal LiNi_(0.83)Co_(0.12)Mn_(0.05)O_(2)(NCM)cathode.The Li-ion conductive Li_(2)TiO_(3) coating layer facilitates the Li-ion transfer and prevents the electrolyte erosion.Meanwhile,the robust Ti-O bonds stabilize the cubic close-packed oxygen framework and mitigate the Li/Ni disorder.The synergy endows the dual-modified NCM with enhanced de-/lithiation reaction kinetics and stable surface chemistry.A high specific capacity of 128 mAh g^(-1) is delivered even at 10 C with an extended cycle life.This finding is reckoned to pave the way for developing high energy density LIBs for long-range electric vehicles.
