Sony has appointed a high-ranking executive to look after product quality and safety, following the fallout from product recalls caused by its faulty batteries. 

Makoto Kogure was previously president of the Japanese giant's TV division. Sony claims that its plans to focus senior executive resources on product quality predate last month's battery debacle.

Dell recalled 4.1 million Sony lithium-ion laptop cells because of a potential fire hazard on 15 August. Apple followed suit on 24 August recalling 1.8 million batteries for the same reason.

Sony estimates that the recalls will cost the company up to $265m. Sony announced that it has changed its battery manufacturing processes to address the issue and improve safety.

The elctronics giant explained how the faulty lithium-ion battery cells could sometimes short circuit, pouring out their stored energy in a runaway reaction which can cause overheating and fire.

"On rare occasions, microscopic metal particles in the recalled battery cells may come into contact with other parts of the battery cell, leading to a short circuit within the cell," said a Sony statement.

"Typically, a battery pack will simply power off when a cell short circuit occurs. However, under certain rare conditions, an internal short circuit may lead to cell overheating and potentially flames.

"The potential for this to occur can be affected by variations in the system configurations found in different notebook computers.

"Sony has introduced a number of additional safeguards into its battery manufacturing process to address this condition and to provide a greater level of safety and security."