Premium
Safe, Low‐Cost, Fast‐Kinetics and Low‐Strain Inorganic‐Open‐Framework Anode for Potassium‐Ion Batteries
Author(s) -
Zhang Ruding,
Huang Jiajia,
Deng Wenzhuo,
Bao Jingze,
Pan Yilong,
Huang Shuping,
Sun ChuanFu
Publication year - 2019
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.201909202
Subject(s) - anode , ion , intercalation (chemistry) , ionic bonding , potassium , electrochemistry , battery (electricity) , materials science , kinetics , open circuit voltage , graphite , chemistry , chemical physics , chemical engineering , inorganic chemistry , electrode , voltage , thermodynamics , composite material , physics , power (physics) , organic chemistry , quantum mechanics , engineering , metallurgy
A key challenge for potassium‐ion batteries is to explore low‐cost electrode materials that allow fast and reversible insertion of large‐ionic‐size K + . Here, we report an inorganic‐open‐framework anode (KTiOPO 4 ), which achieves a reversible capacity of up to 102 mAh g −1 (307 mAh cm −3 ), flat voltage plateaus at a safe average potential of 0.82 V (vs. K/K + ), a long lifespan of over 200 cycles, and K + ‐transport kinetics ≈10 times faster than those of Na‐superionic conductors. Combined experimental analysis and first‐principles calculations reveal a charge storage mechanism involving biphasic and solid solution reactions and a cell volume change (9.5 %) even smaller than that for Li + ‐insertion into graphite (≈10 %). KTiOPO 4 exhibits quasi‐3D lattice expansion on K + intercalation, enabling the disintegration of small lattice strain and thus high structural stability. The inorganic open‐frameworks may open a new avenue for exploring low‐cost, stable and fast‐kinetic battery chemistry.