Retrograded starches as potential anodes in lithium-ion rechargeable batteries.

Retrograded starch is a crystal formed by starch molecules with hydrogen bonds. Many literatures have reported its physicochemical character, but its crystal structure is so far unclear. As we isolate amylose and amylopectin from retrograded maize, sweet potato and potato starches in 4.0 M KOH solutions and make them retrograde alone in neutral solution (adjusted by HCl) to form crystal, a new phenomenon appears, crystals of KCl do not appear in retrograded potato amylose, potato amylopectin, and maize amylose, indicating that those crystals may absorb K⁺ and (or) Cl⁻, and those ions probably act with aldehyde of starch or hydroxy of fatty acid attached in starch, such characteristic may make retrograded starches replace graphite as anode with high-capacity in lithium-ion rechargeable batteries.